View Full Version : Monkey Diving... Simplicity at its best.
Diving without the use of a BC...
An example : http://monkey-diving.com/index.php?option=com_content&task=blogcategory&id=17&Itemid=33
What are your opinions on this form of diving, and why? :smt102
icestac
11-12-2010, 01:42 PM
Looks like fun. Really good marketing for a scooter!
Diving without the use of a BC...
Some of the sidemount rigs don't have a BC or bladder. I've dove the harness a few times in the pool and it actually felt great.
Dark Eternal
11-12-2010, 01:45 PM
I have started to dive a razor in the local lakes with no bladder. When its only 50' deep and all I am wearing is a 3 mil wetsuit and no big lights etc... with 2 AL80s I found I just do not need it.
I have a couple of coments :-)
First and formost, it isn't new. The first time I saw it done was the mid 70's. We had just finished the "Grand Traverse" from Orange Grove to Peacock. Someone needed to retrieve the reel from Orange Grove, so Sheck jumped in wearing a bathing suit, with a single 72 under his arm, and went to get the reel.
If you read the first part of the new sidemount book by Jill, and Brian, they state that Sheck did a recovery wearing one tank. That inspired Wes Skiles to take up sidemount.
Second, why in the world would anyone wear a backplate to dive with one tank???
LiteHedded
11-12-2010, 02:25 PM
looks like power snorkeling to me. i have no problem with it
not new for sure Forrest...
I have been diving without a BC for certain dives and posted that info on SB... I found it interesting the PMs that I received from quite a few people with a varied set of opinions. Some of the opinions were interesting and some came from people who wrote books on sidemount (I hope they post here in an open discussion forum).
Personally, I find it very "free" while diving... :)
diverpaul69
11-12-2010, 02:26 PM
I forget my bcd on a local shallow dive. So I just stuffed some weight into my wet suit. I then held onto the tank and had a great dive. If you know How to use your lungs for buoyancy you don't need a buoyancy control device.
diverpaul69
11-12-2010, 02:29 PM
When I am in Bonaire this winter I think I will experiment with different configuration. Thanks for the ideas.
phillip1
11-12-2010, 03:16 PM
I do all my OW diving with a Razor and just one tank and it's super fun, way more comfortable than a single tank BM by far. for someone who never actually tried it is hard to believe how much better it is in every way.
No hassles on the boat or cumbersome BC's just a single tank and a cam band, in Honduras I let a guy try the Razor, this was an OW diver who had never even heard of SM, he flipped out, got perfect trim right away (he was the same weight and size as me) and could not believe how much better it felt to BM.
Plus it is so much more fun too.
I've done it, but not with a scooter. I even have a video on my website of a dive I did at Cypress with a harness and single 80. If weighted properly, it's a great way to dive.
DA Aquamaster
11-12-2010, 05:11 PM
I used to be real popular at the marina where I slipped my boat. In additon to doing the normal maintence of cables, deadmen, anchors, etc. I was the go to guy when you dropped your wedding ring, sunglasses, etc, off a dock. It was just a lot easier to keep a 40 with a reg on it on the boat ready to go when some one came up with a request. It was slung stage style on a harness and you could walk to where the item was dropped, don mask fins and the 40 and be ready to go in and get it in about 30 seconds. I also did it on my scooter just for kicks - high speed, low drag, great for scooterbatics. In my opinion, an 80 is overkill as a 40 is enough for shallow water when running most small, maneuverable scooters flat out.
I was not aware it was anything special or I guess I could have put it on a web site and called it "larry diving".
I also have done a great deal of vintage diving with single tank, repro cotton harness or vintage back pack and no BC for at least a decade. Great fun, very clean and easy to do with lung volume alone when properly weighted in a 3mm wet suit. Even swimming however you could move fast enough to get the hose on a double hose reg to vibrate, so using a scooter added an additional "problem" with a double hose.
If anything, these guys just re-invented the wheel.
I played around with this in the Red Sea, but didn't really see any significant difference from diving a standard single tank rig.
I've done one day of it in cold water, and was surprised to find that, with no wing, I needed less weight (guess I don't ever get the thing totally empty, huh?) so it felt really good in the water.
A backplate makes a convenient way to sling a tank -- how else would you do it?
It's for shallow, pure fun diving, because you don't have any way to share gas except to buddy-breathe.
SuPrBuGmAn
11-12-2010, 06:01 PM
A harness with D rings allows you to sling a tank without a backplate... and you can always use two 2nd stages and even run them in a way thats hog-ish :)
icestac
11-12-2010, 07:00 PM
Personally, I find it very "free" while diving... :)
+1 - I think that is the best expression
phillip1
11-12-2010, 07:37 PM
I played around with this in the Red Sea, but didn't really see any significant difference from diving a standard single tank rig.
I've done one day of it in cold water, and was surprised to find that, with no wing, I needed less weight (guess I don't ever get the thing totally empty, huh?) so it felt really good in the water.
A backplate makes a convenient way to sling a tank -- how else would you do it?
It's for shallow, pure fun diving, because you don't have any way to share gas except to buddy-breathe.
I set up my first stage with two regs one around my neck and one octopus "long" hose tucked in like on a regular left SM tank, super easy set up and really comfortable + even more comfortable to share air if need be. Just an all round super fun, uncluttered way to dive OW
OneBrightGator
11-12-2010, 08:34 PM
Second, why in the world would anyone wear a backplate to dive with one tank???
Just guessing, but maybe for the weight or because they already have it.
Slüdge
11-12-2010, 08:47 PM
More than likely it all comes down to the psychological issues.
limeyx
11-13-2010, 05:46 PM
A backplate makes a convenient way to sling a tank -- how else would you do it?
Faisal in the Red Sea has a pretty interesting way :)
Works best with an AL40 or other small tank though.
saxplayer1004
11-13-2010, 06:27 PM
I use the stage straps, and a weight belt with a D ring on it. We dive like this in the pool all the time. err well some of us do. We baretank as well which is really liberating. If we're monkeying around in the pool I prefer no BC, it's just irritating sometimes. This takes MUCH less time, much less stuff to go wrong. I think it's really helpful to figure out how your buoyancy is on your own. If you know how much air you can breathe and still be able to stay neutral or negative, that's incredibly important if you have equipment failure, especially in a cave or a wreck
phillip1
11-13-2010, 07:16 PM
yeah I agree, from diving the Razor (or similar stripped down harness) you realize how messed up one's buoyancy really is, the Nomad and co all float and you end up using trim weights just to stay neutral, I used up to 7lbs with my Nomad and then also with my dillo. Using the exact same 7mm wetsuit I use no weight at all with the Razor and can control my buoyancy perfectly even with tanks down to 50bars each. in the ocean with a 5mm suit and a single AL80, I use 4lbs and it works perfectly.
CaveBuddy95
11-13-2010, 09:11 PM
I don't see the need to criticise Monkey diving, it definitely looks fun. But don't go Monkey diving if you don't have an Xscooter... :)
As long as it is not called sidemount diving it's fine. Go backplate if you want, build your own Monkey diving rig or if you've got the $, you can buy the Z stuff from the not GUE but look a like agency :) as long as it's not called sidemount diving. It would create confusion and thats counter productive!
What Phillip is doing, if I may, is single tank sidemount diving. While using the best invention there is for cave sidemount diving, the Razor, it allows tanks to stay trimmed during the whole dive. No light tank butt issue at the end of the dive for Phillip. Which is different from jumping in the water with a stage tank and just go for it.
There's been some bandwagon jumping lately with sidemount and it's great, because it creates interest and discussion. But if you haven't noticed yet, I defend sidemount and Monkey diving, is not sidemount.
Poll question:
What is most DIR? Monkey diving or sidemount diving with long hose from right tank and bungeed reg for left tank?
.
.
.
phillip1
11-14-2010, 09:12 AM
In OW I dont use a long hose but a octopus "longer' hose. But anyway anyone who would actually try either monkey diving or single tank SM would have to agree it is way more comfortable than a single BM tank.
All things being equal safety wise, the one most important feature of single SM is that it is waaaaaaay more fun than single BM, (notice I did say all things being equal safety wise). For me that is why I dive to have fun, I don't care about what I look like or even what config I dive as long as I am safe and the most efficient I can be, I want to have fun so as I stated above if two rigs are just as safe but one is waaaaay more fun it's a no brainer, BM is just not as much fun, period.
Slüdge
11-14-2010, 09:52 AM
anyone who would actually try either monkey diving or single tank SM would have to agree it is way more comfortable than a single BM tank.
Of course. What kind of moron would put the cylinder on their back where it's out of the way and symmetrically balanced?
phillip1
11-14-2010, 10:34 AM
The kind of moron who took the time to actually try this configuration and who discovered that it is in fact not off balance at all very streamlined and waaaaaaaaaaaay more fun...
OneBrightGator
11-14-2010, 10:50 AM
After watching a few of AGs videos it sure looks like they're trying really hard to squeeze something else in besides traditional BM or SM. I don't quite see the point, the gas block and everything else seems a lot more complicated than just using a standard stage bottle. I also don't understand how you manage up to a 5.8 lb. weight shift on one side of your body. I could tell a difference with two sidemounted LP85s that had 1000psi difference in them and it was pretty annoying. I've never tried single SM/monkey diving though.
saxplayer1004
11-14-2010, 11:05 AM
I stick the tank right underneath my body when I'm monkey diving in the pool. I don't know how you can say that one tank off of your body is not off balance. Unless you have something equal to offset it, it's off balance. No tank is perfectly neutral, certainly not when it's full vs. empty, the regulator throws the bottle neck down, and all of that is off of one of your hips. I don't think it's any more streamlined than doing backmount single with no BC. No way. It's the same equipment. Is it more comfortable, sure, but at the same time it still throws you off balance. If you're monkeying around in middle water with a scooter it's cool, or if you need to jump in and fetch something really quick, but I can't see it being any better than sidemounting two bottles
phillip1
11-14-2010, 11:06 AM
single SM (with Al tanks) is great and not off balance in any way at all, steels would probably not work at all
I have to admit, I thought it would be terribly off balance, but it wasn't -- I guess whatever it is that I do to balance a couple of extra bottles on one side, I can do with no tank on my back at all.
I just didn't find the extra "fun" that people write about. I did the "Three Wrecks" dive in the Red Sea, and it was fun to scooter three wrecks, but it would have been just as much fun in a backmounted single tank, I think. When I did the swim dive in Puget Sound, I did appreciate carrying less weight, but I swim more efficiently with the cylinder on my back, because of the inevitable sway of a slung cylinder.
Edited to add that this "manifold" thing that AG is promoting is a brand new thing they've come up with, and everybody I know who monkey-dives (and a lot of my friends, for whatever reason, do this) does not use such a convoluted setup.
OneBrightGator
11-14-2010, 11:40 AM
single SM (with Al tanks) is great and not off balance in any way at all, steels would probably not work at all
...sigh... the type of bottle has no effect on the buoyancy shift.
How many times do we need to go over this???
CaveBuddy95
11-14-2010, 12:46 PM
Tanks sway can be avoided if you set yourself up in Bogaerthian sidemount configuration. The time spent adjusting the Razor, the d-rings and the bungee makes tank trim and streamline, a no-brainer. Even with just one tank. Tank swing occurs probably because they are set up as 'stage' tanks - if you lower the SS hose clamp band and get rid of stage kit, just bungee around the modular or non-modular valve, it sticks to you like there is no tomorrow... ;) Haaaa, the beauty of training, it's so refreshing! :)
phillip1
11-14-2010, 01:07 PM
...sigh... the type of bottle has no effect on the buoyancy shift.
How many times do we need to go over this???
Have you ever tried a properly set up (for you) Razor style harness? if not it would be very hard for you to understand that you are not off balance at all and that lung volume alone is all that is needed to perfectly control buoyancy throughout the dive, from full to empty tanks. This also applies to regular two tank SM too.
This is all with AL tanks, with steel I don't know, never dive steels here or anywhere.
Slüdge
11-14-2010, 01:11 PM
Ben, you goofus, don't you know somebody's come out with cylinders that weight the same full as empty?
phillip1
11-14-2010, 01:35 PM
It's obvious you have never tried this kind of harness, but that is not the point, yes buoyancy does change between full and empty tanks, duhh, it's just that with a properly set up Razor type harness it is not an issue and that lung volume alone is enough to perfectly control the buoyancy and that clipping the tanks at the right moment will help keep the butt/butts down
But unless you actually try it it's impossible for you to understand what it's like, hey before I tried it I was not convinced either, an open mind, what you need is an open mind my friends....
Slüdge
11-14-2010, 06:15 PM
it is not an issue and that lung volume alone is enough to perfectly control the buoyancy
I know some readers are tired of me asking you this, but you keep going on and on about it and have never answered the question - you have been talking about two side cylinders and a stage, breathed down to a third. How do you compensate for an eighteen-pound buoyancy shift?
phillip1
11-14-2010, 06:57 PM
Since I started diving the Razor I use no weights in freshwater, at the start of the dive with 3 AL 80's I am slightly negative under 10M, during the entire dive I am perfect and at the end of the dive I am slightly positive above 3mtrs. After training with Steve in Mex I learned to fine tune the Razor to perfection, I probably would never have gotten it so perfect with out Steve's training and advice.
what I have learned is that a "BC" type harness like the Nomad or dillo harness float a lot about 4-5lb positive as is so you add trim weights and such just to keep neutral, The Razor is really precise in that you can fine tune it to the extreme and get it so you use no or very little weight.
I am thin so I use no weight by Thomas who is a bit bigger that me uses a 2LB weight with a 7mm suit and a 3mm hood.
I am not very eloquent when it comes to why it works, but I swear it does, that is how I dive every time, hopefully Steve will read this post as he could explain it much better than me.
Anyway you should try a razor type harness if you ever get the chance, it will surprise you, AL for sure, steel tanks dunno don't use em
phillip1
11-14-2010, 08:23 PM
Ok so I got thinking a bit, when I used to dive BM I had a SS backplate that was 5lbs negative, I used a 5mm suit and no weights, I would do stage dives with 3 AL 80's and have little to no air in the wing. When I switched to the Nomad I used 2X3lbs trim weights, then switched and had 2X4lbs trim weights and the same 5mm suit, I would use little to no air and do stage dives with 3 AL80's.
The Nomad basically is about 2-3lb positive and maybe more if you use a lumbar pad, (about the same as a wing and backplate + lumbar pad)
Now in those above mentioned configs I had no problem with buoyancy throughout my dives and the tanks shifted in weight exactly like they do now, I used little to no air in my wings and it was fine.
Now I dive a Razor with no weights (freshwater) a 7mm suit and up to three tanks on lung volume alone, it works great in fact way better than any other config I have ever tried, if you throw the Razor alone in the water it will have neutral to no buoyancy, add a light canister or reel and it will sink, not the case with a BP and wing or Nomad/Armadillo setup.
So I think that using lung volume and no weights with a 7mm I am pretty much about the same buoyancy wise as a 3-4 positive Nomad with 6lbs trim weights, except I am much more fine tuned in the Razor, in the Razor even the choice of fins will have a huge impact on trim/buoyancy.
Whatever, both BM and SM work fine, it's just that I really do not like lugging doubles around and I like tight caves and most of all I really have much more fun SM, hey some people might even prefer playing darts to cave diving for all I know.
DA Aquamaster
11-15-2010, 07:30 AM
I think people are getting wrapped around the axle regarding theory and are ignoring the bigger picture.
1. The difference between a single back mounted AL 80 and a single slung AL 80 used with a harness is that you have a lot more flexibility along the length of your back. That equates to greater freedom of movement and greater ability to maneuver the scooter, especially a scooter with a free floating bolt snap on the tow cord.
2. An AL 80 shifts from about a pound negative when full to about 4 pounds positive negative add a stage reg and SPG and, if you prefer an octo bungeed to the tank, and it goes from about 3 pounds negative to 2 pounds positive during the dive. It is indeed going to be off balance, but it is not a huge shift.
3. More importantly, you are flying a scooter. A scooter that is developing torque already and a scooter that is providing substantial forward motion in the 200-250 fpm range depending on the scooter and how streamlined you are. That allows you to easily offset the slight out of trim condition with just a slight change in angle on a fin, and you are already doing that to some extent to offset the torque and maneuver the scooter.
So being slightly out of trim truly does not matter, but having greater freedom of movement does.
Now...let's get back to the regularly scheduled nit picking and "how many angels can you fit on the head of a pin" discussions.
2. An AL 80 shifts from about a pound negative when full to about 4 pounds positive negative add a stage reg and SPG and, if you prefer an octo bungeed to the tank, and it goes from about 3 pounds negative to 2 pounds positive during the dive. It is indeed going to be off balance, but it is not a huge shift.
Hmmm, a single 80 "monkey style", and a stage bottle on the other side? That would be called???
DA Aquamaster
11-15-2010, 03:54 PM
Hmmm, a single 80 "monkey style", and a stage bottle on the other side? That would be called???No Forrest - only one bottle - an AL 80 with a stage reg on it. The diver could add an octo if he/she prefers. I don't prefer that as "fail closed" failures with a second stage failures are extremely rare, so there is no real need unless the diver is OOA and in that case, on a scooter on a shallow NDL dive, accessing the surface is faster than catching the buddy to share his or her gas so a buddy's octo is of very limited utility.
The stage reg approach would be in contrast to whatever other regs other people put on them when they monkey dive. The point being an AL 80 with reg is not overly negative or positive during the dive as the swing is from 2-3 pounds negative to 2-3 pounds positive.
Got this in a PM on another site, and I thought I would do what the author asked... I know he mentions OW, but maybe these are things to ponder for cave (the rescue one especially)... ( have already responded via PM with my rebuttals, but I figured I would see what others thought as well)
-----------------------------------------
Hi Joe,
Hope all is well. I'm new to the site and was just sorting through some of the side mount threads. I feel like I needed to state my case without trying to flame anyone in public concerning the use of any open water side mount configuration without the use of a BCD. I honestly feel that there is a huge safety issue when this configuration is used in open water without the addition of a proper BCD (and not a drinking water bladder).
Open water divers are exposed to strong currents on the surface, as well as the possibility of surfacing away from the boat or in rare cases coming to the surface and the boat being gone. This places the diver in an extremely unsafe situation.
In the event that a side mount diver were required to rescue another diver (or reverse) the lack of a BCD on either diver could have dire consequences. I hope that as a diving instructor, you can see my concern especially when posts like this are given to new divers by an experienced cave diver and instructor such as yourself.
---------------------------------
I have to agree with him on the BCD. You can get all the "benefits" of a Monkey dive, and still use a standard OW BCD.
phillip1
11-15-2010, 04:45 PM
I really doubt that when I dive should I need to rescue someone or vice versa the lack of a BM BC will make any real difference. If I surface and the boat is gone if need be I will ditch all my gear except mask and fins and be able to float no problem and swim, If I am unconscious and the boat is gone well I guess I am dead then anyway, might as well be SM and go out in style.
In a cave my body be will fairly neutral at all times and it will be pretty easy for anyone to pull me out if need be as far as me being buoyant etc... But being realistic in a cave having to drag your unconscious buddy from way back in a cave is not really feasible, I would try for as long as my air permits but I think that would only be possible if you had a relatively short distance to go.
I tried it once with Thomas a while ago he acted as the dead guy and it is unrealistic to think you could pull someone out from very far back.
I have dove many many times on boats SM, double BM, single BM and I think that if you are diving SM with one tank and actually spend the time to weight yourself properly instead of the traditional way overweighted OW diver, you will end up using minimal weight and be able to stay afloat no problem, in a real emergency you can ditch the tank and loses even more weight I guess.
I mean a BC is a BC not a life vest for god sakes!, what about wreck divers who use two stages and doubles in that case, and the wing fails, are they being unsafe too? yet it is not unsafe to dive that way nor is it considered to be and it is done worldwide on a daily basis.
I think this Instructor speaks out of pure ignorance of SM and SM with Razor type harnesses, just MHO
I woud be more concerned about untrained OW divers going cave diving if I were him, not about trained cave divers going OW diving,,lol...
DA Aquamaster
11-16-2010, 06:43 AM
"Monkey diving" and "cave" are terms that don't belong in the same post due to the lack of redundancy so don't confuse things with a discussion of cave diving without a BC - it's a totally different issue.
-----
With that aside, I also don't agree there is excessive risk in not having a BC when monkey diving. I spent a few years free diving before I started scuba diving and it taught me the benefits of being properly weighted and using wet suit compression to your advantage both on the dive and when resting on the surface.
When I started diving it was suggested that the practical recreational no deco dive depth limit should not be defined as 60', 100' etc, but rather twice the depth to which I could free dive. The assumption being if everything else (including the buddy) failed, a free ascent was a viable option. I don't see that being any different with monkey diving.
In terms of OW diving, the BC only indirectly made diving "safer". The direct impact was that a BC made it "easier" and less physical as it greatly reduced the effort needed to swim, that then made it "safer" for divers with lesser ability in the water. The argument in an overhead is different as the BC adds a level of precision that was previously absent and allows for an otherwise absent level of safety with heavy steel tanks, etc. But again that is not a consideration in monkey diving.
So in essence the BC concern is not relevant when you essentially have a properly weighted free diver diving instead with a harness, tank and scooter on reasonably shallow no deco dives where redundancy is not really an issue.
"Monkey diving" and "cave" are terms that don't belong in the same post due to the lack of redundancy so don't confuse things with a discussion of cave diving without a BC - it's a totally different issue.
So you're stating that the way Steve Bogaerts dives in the caves (no BC except when using stages) shouldn't be done?
DA Aquamaster
11-16-2010, 08:12 AM
So you're stating that the way Steve Bogaerts dives in the caves (no BC except when using stages) shouldn't be done?Do you have a learning disability or print impairment or are you just being argumentative? Personally, I have seen no evidence of the former so I susepct the latter but I won't assume your intent.
It's obvious I'm not stating what you've attemped to paraphrase from my quote - and it's clear in my previous post.
Cave diving without a BC is a different issue separate from monkey diving - and it is a monkey diving thread.
If there is any similarity it is that how Steve Bogaerts dives is key in terms of tanks used, depths and water temp/exposure suit used. The critical issue is that buoyancy can still be controlled with lung volume alone (or with hydration bladder) making a BC unneccesary. But that is very much a systems issue where changing any one of the factors can make diving sans BC no longer viable.
In short, it's important tfor people to understand what is going on rather than just regurgitate standard lines or dogma that may or may not be related to what's being done or discussed.
OFG-1
11-16-2010, 09:50 AM
Kinda looks like this:
http://1.bp.blogspot.com/_s4kKiT-Jhao/TEU4cNopTVI/AAAAAAAAB7Y/ObSdxbUha9M/s400/LloydBridges.jpg
Do you have a learning disability or print impairment or are you just being argumentative? Personally, I have seen no evidence of the former so I susepct the latter but I won't assume your intent.
It's obvious I'm not stating what you've attemped to paraphrase from my quote - and it's clear in my previous post.
Cave diving without a BC is a different issue separate from monkey diving - and it is a monkey diving thread.
If there is any similarity it is that how Steve Bogaerts dives is key in terms of tanks used, depths and water temp/exposure suit used. The critical issue is that buoyancy can still be controlled with lung volume alone (or with hydration bladder) making a BC unneccesary. But that is very much a systems issue where changing any one of the factors can make diving sans BC no longer viable.
In short, it's important tfor people to understand what is going on rather than just regurgitate standard lines or dogma that may or may not be related to what's being done or discussed.
Actually... since I opened this thread as one that revolved around discussion of the idea of "monkey diving" on a forum suited for cave diving, I may be asking people's opinion on applying the concept to cave diving...
Since you apparently are a single thread kind of guy... I'll remind you when you make posts from here on out that are "off topic" to the original thread post... Which may be quite often...
Aside from that...
What is your opinion on diving in a cave with 2 AL80s, harness, and a wetsuit? Should it be done in that manner?
:)
DA Aquamaster
11-16-2010, 03:36 PM
What is your opinion on diving in a cave with 2 AL80s, harness, and a wetsuit? Should it be done in that manner?It depends on the depths involved, the water temp/wet suit thickness. In a shallow cave in warm water with no great need to use a large percentage of the available gas, then maybe.
Again the critical criteria is whether precise buoyancy can be accomplished on lung volume alone, meaning mostly whether the swing weight of the gas used on the dive can be accommodated with lung volume with the added compliction of any compression of the exposure suit.
If you are using 2/3rds of the gas even in AL 80s then the swing weight will exceed the practical limits of what you can do with lung volume alone. The gas and or buoyancy requirements will limit the types of caves/environments where this approach would work.
It's also increasingly impractical as the swing weight of the gas increases, as it begin to interfere with an efficient breathing pattern. personally I think it makes a great deal of sense from that perspective to use a reasonably small bladder to accommodate the swing weight of the gas as well as suit compression - even in warm water.
It depends on the depths involved, the water temp/wet suit thickness. In a shallow cave in warm water with no great need to use a large percentage of the available gas, then maybe.
Again the critical criteria is whether precise buoyancy can be accomplished on lung volume alone, meaning mostly whether the swing weight of the gas used on the dive can be accommodated with lung volume with the added compliction of any compression of the exposure suit.
If you are using 2/3rds of the gas even in AL 80s then the swing weight will exceed the practical limits of what you can do with lung volume alone. The gas and or buoyancy requirements will limit the types of caves/environments where this approach would work.
It's also increasingly impractical as the swing weight of the gas increases, as it begin to interfere with an efficient breathing pattern. personally I think it makes a great deal of sense from that perspective to use a reasonably small bladder to accommodate the swing weight of the gas as well as suit compression - even in warm water.
Since you are saying so much on the subject of diving without a BC, I can only conclude that you have have tried it yourself and are speaking from experience, right?
SuPrBuGmAn
11-16-2010, 04:57 PM
When has actual experience ever been important before a metric load of yacking spewed onto the interwebs?
DA Aquamaster
11-16-2010, 07:46 PM
Since you are saying so much on the subject of diving without a BC, I can only conclude that you have have tried it yourself and are speaking from experience, right?Yes...post #11 covered that already.
dogwatch
11-17-2010, 10:00 AM
I have to agree with him on the BCD. You can get all the "benefits" of a Monkey dive, and still use a standard OW BCD.
In the mid 80's, I had the chance to check out a spring that feeds the Chipola. Some non-caving friends had moved some debris and thought i could sqeeze in. I didn't want to push double 104's in on the first try for several reasons. I decided to get a Y-valve for my stage, rig two regs, wear a plate and mount it like a stage. I wore an old USD BCII, some lead and a canister and back-up lights. It worked well. It never occured to me to bring two bottles (side mount style), but that would have been better - i kept looking at the neck O-ring to fail :).
As an aside, the spring checked out. I think i was the first in, as it had no line. I reeled my line out because i didn't like how it was configured and planned to come back with full gear and help from the pros. Unfortunatley Woody got to it before we could get back and claimed it :). Not sure what it is called.
SuPrBuGmAn
11-17-2010, 01:05 PM
If I sent you a photo or two, could you identify the spring if its the one you were taking about?
dogwatch
11-17-2010, 01:53 PM
If I sent you a photo or two, could you identify the spring if its the one you were taking about?
It's worth a try. A have a grainy photo of the spring from a distance an one of me in the funky rig standing in the water to try and compare with.
Brian Kakuk
11-24-2010, 06:38 PM
Got this in a PM on another site, and I thought I would do what the author asked... I know he mentions OW, but maybe these are things to ponder for cave (the rescue one especially)... ( have already responded via PM with my rebuttals, but I figured I would see what others thought as well)
-----------------------------------------
Hi Joe,
Hope all is well. I'm new to the site and was just sorting through some of the side mount threads. I feel like I needed to state my case without trying to flame anyone in public concerning the use of any open water side mount configuration without the use of a BCD. I honestly feel that there is a huge safety issue when this configuration is used in open water without the addition of a proper BCD (and not a drinking water bladder).
Open water divers are exposed to strong currents on the surface, as well as the possibility of surfacing away from the boat or in rare cases coming to the surface and the boat being gone. This places the diver in an extremely unsafe situation.
In the event that a side mount diver were required to rescue another diver (or reverse) the lack of a BCD on either diver could have dire consequences. I hope that as a diving instructor, you can see my concern especially when posts like this are given to new divers by an experienced cave diver and instructor such as yourself.
---------------------------------
And on another post concerning the above on another post: "I think this Instructor speaks out of pure ignorance of SM and SM with Razor type harnesses, just MHO"
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Just so that it is clear, I am the one who posted that PM to Tegg. If you look at ANY standard for ANY open water course, instructor equipment requirements etc., you will find that use of a BCD is mandatory. My only issue is using a Razor or similar harness only system in OPEN WATER, and Instructors or other divers posting pictures with other open water divers in the background is inappropriate. I have NO problem at all using the Razor for it's intended purpose, which is accessing SMALL cave. It is an awesome rig for that purpose.
There are many times when diving a harness without a BCD device in open water is appropriate. These generally are commercial diving operations where no cylinder is worn at all and the diver is tethered to the surface with an umbilical. I've used this mode for many, many years as a Navy hard had diver and commercial diver in every type of hard hat or full face mask imaginable, and the freedom it permits is fantastic for the underwater work site. It is completely unsafe (in my apparently uninformed and inexperienced opinion) for open water recreational diving without the inclusion of an appropriate BCD.....NOT a water bag.
My prediction is that some folks will continue to do this type of diving, and eventually someone will drown when their scooter shits the bed, far away from the boat in heavy seas and or in a current. I hope I am wrong but I’m not. I also believe any instructor conducting courses in this configuration in OPEN WATER that is too deep to stand up in should lose their teaching credentials. It is my understanding that Joe was NOT teaching any courses at the time and that he was simply conducting the dive that I questioned, on his own time and for his own pleasure.
Safe diving,
Brian
phillip1
11-24-2010, 06:54 PM
I think I wrote that post and not only do I stand corrected but I also feel extremely stupid I made such a comment since you are the instructor in question and a 10th degree black belt in SM no less!!!
Brian Kakuk
11-24-2010, 07:18 PM
I think I wrote that post and not only do I stand corrected but I also feel extremely stupid I made such a comment since you are the instructor in question and a 10th degree black belt in SM no less!!!
Not an issue at all Phillip. We all feel the way we feel based on what we have seen and what we have experienced or what others have taught us. You feel the way you feel about it, and you shouldn’t be afraid to voice it in any way shape or form. As I said in my original message to Joe, I feel VERY strongly about the subject, so felt compelled to reach out to him, not as someone trying something new, but as an instructor who up and coming divers look to for what is safe and what is not. I would not have written my last post had Joe not already posted my PM message to him.
As I have written before, I applaud the divers who try something new. That is how we have evolved in this sport. This point is made in the photo of Lloyd Bridges (we called him Lloyd Bilges in the Navy) with his back mount, no BCD set up. There were NO BCDs when that photo was taken of our illustrious diving forefather. We evolved when someone decided that diving that rig was not nearly as safe for recreational divers without the need for some method of achieving complete positive buoyancy for emergency situations.
I think I've been given the opportunity to make my position clear. I hope you will always feel you can do the same.
Safe diving,
Brian
CaveBuddy95
11-24-2010, 08:31 PM
Unfortunately, teaching in a Razor like harness with a water bag as you say, is already being done, in open water. Not by an isolated instructor but by one of the most active dive shop in Latin America, for example. One with all the palms and stars credentials.
It is even more worrying that with the recreational teaching system (by professional diving instructors FWIW) as open water sidemount is being taught, new instructors can also begin to teach open water sidemount with the same minimalist approach we use in sidemount caves...Hello??? What is going on here?
If we worry about non-cave certified divers entering the overhead environment, what about those open water sidemount divers, using inappropriate scuba equipment..??
Then what could happen is that "our" way of diving is going to be stated as inappropriate due to a handful of dive pros, just wanting to enjoy the sidemount frenzy.
Monkey diving should not be backed up by any agency and proper sidemount BCD should be used when sidemounting, during and after courses. Local legislation applies...of course! :)
Difference needs to be made between cave sidemount and open water sidemount - not talking about monkey stuff here
It is completely unsafe (in my apparently uninformed and inexperienced opinion) for open water recreational diving without the inclusion of an appropriate BCD.....NOT a water bag.
Brian,
Thanks for coming on and stating your opinion. Open exchange of opinions is what this site is all about and I think that open discussion of topics such as this one make for a better overall understanding.
As to the line above... Can you explain the difference of a MSR "water bag" to which I have installed a standard BC inflator hose and BC pull dump and a "appropriate BCD"? I am interested in the difference you see.
My prediction is that some folks will continue to do this type of diving, and eventually someone will drown when their scooter shits the bed, far away from the boat in heavy seas and or in a current. I hope I am wrong but I’m not. I also believe any instructor conducting courses in this configuration in OPEN WATER that is too deep to stand up in should lose their teaching credentials. It is my understanding that Joe was NOT teaching any courses at the time and that he was simply conducting the dive that I questioned, on his own time and for his own pleasure.
Safe diving,
Brian
Just as you know, sidemount had many people saying it was an inappropriate configuration for OW use for many years and it is ONLY NOW getting seen as a configuration that may be useful for things like wreck diving, etc.
All configurations of diving have their uses. Anyone who takes a "razor" style sidemount rig in heavy current or rough seas, will find themselves very uncomfortable and possibly dead. The rig is not designed for those kind of conditions. Then again, neither are a lot of the "standard BCs" you speak of.... One would need to pick the best rig for the planned dive and planned situation. The use of a "razor" style rig in calm seas and low to moderate current is quite acceptable to those that understand the risk and have the experience to know what they are getting themselves into. I dove my configuration in almost glass seas in the keys with all of my "safety equipment" for those conditions. I posted the picture of that because I feel that a diver with decent experience who has been taught how to use the rig would find the dives enjoyable in that configuration, as I do. Just like posting pictures of someone going into a "cool" cave should not be considered "irresponsible" because a bunch of OW divers may think of going into a cave lacking training or experience.... My posting of pictures in that configuration is no more irresponsible. There needs to be a certain level of PERSONAL RESPONSIBILITY. If a person makes a choice to dive a certain way, then THEY make that choice.
As far as instructors teaching with this configuration in the OW, I guess you are saying that Steve Bogaerts should loose his teaching credentials? (http://www.gosidemount.com/courses.asp) He teaches a "Basic Sidemount Open Water" 3 day course which uses this configuration.
As to the past portion of your post, You are correct. I was diving in that configuration on my own time and not teaching a course. I know it is a shocker to some of the people on this forum... but I do dive in the open water on occasion... :diver
Brian, I thank you for coming on here and openly stating your opinions and I hope that you answer the questions I posed above. This open discussion is good for the ones considering using this configuration for certain types of dives and I think it's good for them to hear opinions from the whole cross section of divers.
OFG-1
11-26-2010, 07:10 AM
Hi Joe;
OK, I guess I can add a bit of crap here. When I took my OW lessons in 1967, there were only a couple of options for BC's, and they really were the old Mae West vests, strictly for emergencies. We were taught to achieve neutral buoyancy at the surface with all gear on. If you looked at a group of divers, when they descended, you would see a bunch of people having to perform a surface dive to get underwater. Drop your belt and you were positive.
When the horsecollars became available, and PADI and NASDS relaxed standards, then we saw the elevator type diving that we still see in OW today. Weight the hell out of yourself, push a button go down, push another come up.
In the old days, divers actually had to be able to swim. Not a little like today, but a lot. Swim with fins, without, with snorkel and mask, without. When I went to commercial diving school in '73, they loaded us in a landing craft, took us 4 miles offshore, and we swam back in with mask fins snorkel.
The point, BC's became a replacement for good swimming skills. It allowed a lot of people that were marginal swimmers to go out and get certified and spend money and pump up the dive business.
I believe what Brian is saying is that when you remove this crutch, then a lot of people that are OW divers are going to be in an instant emergency, and some will cack themselves cause they cant swim. I have recovered divers in the 70's, with BC's on, that would drown before they would dump their weightbelt or tanks. And yes, if I had my preference and was still teaching diving, I would teach with a horsecollar any day over a jacket. Why, you can dump off everything except your BC. I still dive OW with a Sea Quest horsecollar BC, and I have dumped everything more than once.
That brings us to the MSR bag, and we may extend this to the old Brawley pillow. The center of buoyancy for these is not in a place that allows for comfortable rest on the surface. Now we could unclip the pillow and rest on it, but at that point, it was not attached to us.
The horsecollar and modern jacket were designed to support someone head up, with their face out of the water, with a LOT of excess lift. That's the difference, and that's why for OW diving "monkey diving" should not be taught, or at least not until a advanced stage. If a bunch of people start seeing this on the boats, then it will be viewed as a good idea for everyone. Its not.
The horsecollar and modern jacket were designed to support someone head up, with their face out of the water, with a LOT of excess lift. That's the difference, and that's why for OW diving "monkey diving" should not be taught, or at least not until a advanced stage. If a bunch of people start seeing this on the boats, then it will be viewed as a good idea for everyone. Its not.
Maybe if diving was taught properly, there would be no issue. Most back inflation BCs (a lot of the BCs sold these days) will put the person's head into the water at the surface if the diver panics and fully pumps the BC. Yet those types of BCs are "OK"? There seems to be a lot more "deaths" from divers NOT ditching their weightbelts and/or gear and drowning then those who seem "smart enough" to save themselves. So having the ability to remove gear from most of these OW divers seems pointless.
I equate this to people driving cars. Some people still choose to drive old cars with no safety features and no power steering. Those vehicles are "harder to drive" and take a lot more skill to drive properly, which may be the reason people like to drive those cars. The general population shouldn't even think about driving cars like that because in reality they would "cack" themselves in a short time.
Should I restrict my diving enjoyment simply because the majority of instructors out there short change their students and teach them crap diving skills and don't teach them that they need to know what they can dive and how they can dive it by making their OWN proper decisions?
CaveBuddy95
11-26-2010, 08:06 AM
If I may, horse collar or any BCD for that matter, are not design and/or specified as a Life jacket . It supports the diver at the surface, thats all. Now, and you are right I think, in the unlikely event where **** hits the fan, you can always (if you were taught of course) drop your weights and this only should ensure ample flotation.
The MSR concept was brought up for tight cave passages, where buoyancy is not an issue. On top of that, the idea behind this is to minimalize the amount of weight needed. Just the need to compensate what in our gear is positively buoyant, and this type of diving, there is not much. It is also very easy to drop all the tanks if safety is at stake. And unclip the MSR and use it as a flotation device. Ok, it is not approved or made for that use but it works. If concerned, carry a back up one.
As it was said earlier in this thread, if the diver accept the consequences, then, no problems. And I think at that level, divers are conscious enough to make the right decision.
Here for instance (Mexico) there is no such a strong liability culture :)
(and plenty of jungle with wild animals to get rid of evidences...just kidding...just kidding...Am I??)
;)
phillip1
11-26-2010, 08:40 AM
I think that if you actually need floatation for a long period of time then **** has hits the fan big time and you are either lost at sea, or the boat has left you.
Now either you have not underestimated the fact that in any ocean diving you should always have a whistle and an SMB and are very lucky, the ocean is fairly calm and they find you or you are dead.
If you surface unconscious from a dive your chances are slim and you are in very deep **** already, now either you are solo and are dead or with a buddy who can easily dump your gear and pull you afloat at the surface with or in my case without an SMB or wing as I float a lot in wetsuit.
However I am not an instructor and this is how me and my buddies dive, I think that it takes a lot more commitment and training to dive a Razor type harness and that a regular average OW diver may be "safer" in a regular jacket BC.
I may be wrong as I have zero experience teaching or dealing with OW divers, but for my diving it seems safe to me to dive in a Razor or at least just as safe as a jacket BC.
I dive spots in the ocean that are relatively close (1-2ks tops) from shore and surf many of those same reefs on days with good swell, I do no think diving them with a Razor is any more dangerous than surfing there, it is actually probably safer as when I am diving I use a wetsuit and actually float but I am in board shorts when surfing and do not.
khacken
11-30-2010, 01:42 AM
My last trip to Cozumel, I used a Hollis SMS 100 with the wing off, a 6L MSR mounting on my back in line with the spine, dove with a single tank of the left side and bungied a three pound weight to my right wrist for counter weight. As backup floatation, I always carried my smb.
What I found what that with that setup, I actually floated more relaxed when waiting for the boat, as my head was further out of the water.
Also, the dives were incredible as I was able to enter into swimthroughs that I would not enter otherwise for fear of damaging the reef. These were amazing!
So, my question is this, as already stated is the issue with MSR bags in the construction of the bag itself, or is it the lift, or is it the lack of a power inflator and OPV?
...So, my question is this, as already stated is the issue with MSR bags in the construction of the bag itself, or is it the lift, or is it the lack of a power inflator and OPV?
All of the above :roll:
An OW jacket BCD is plenty streamlined and compact. It is tougher, and has plenty of lift, as well as power inflator and OPV.
DA Aquamaster
11-30-2010, 05:24 AM
UTD was at DEMA and Andrew has an excellent monkey diving rig in prototype/pre-production form
It is in essence a razor'esque harness with a 15 pound trim bladder mounted low on the back with POV and a Edd Sorenson/nomad style corrogated hose routing. A 30 pound bladder is in the works.
It also incorporates a manifold mounted on the upper plate that along with a QD equipped hose routed under a neoprene shoulder pad on the left shoulder brings the gas from the tank to the manifold to distribute it to a conventional long hose and bungee back up hose confriguration.
In effect, it resolves the lack of octo, OPV and power inflator concerns and does it with a variation of standard hog hose routing.
It also obviously has potential sidemount applications as there is room on the manifold for another hose feeding from a right hand tank, but Andrew is not promoting it that way (yet?).
SuPrBuGmAn
11-30-2010, 06:25 AM
The UTD monkey diving rig is someone intriguing... but the little manifold thing they use is absolutely unnecessary.
phillip1
11-30-2010, 07:14 AM
Then surfing outer reefs is super dangerous cause we paddle out and use no buoyancy devices of any kind.
Really and truly if you actually need emergency floatation for more than 5 mins you are probably lost at sea or the boat left you in which case you are in deep **** and having a large SMB would be of much more importance than a BC or MSR bag I think.
DA Aquamaster
11-30-2010, 07:20 AM
The UTD monkey diving rig is someone intriguing... but the little manifold thing they use is absolutely unnecessary.No argument there regarding it being neccesary. But the underlying concept has some merit and the idea is to allow standard hog/DIR hose routing to maintain commonality with standard backmount hose routing.
From the perspective of how it is currently marketed (monkey diving) it makes sense to stay with standard hose routing as opposed to a single tank with single second stage with perhpas an octo bungeed to the tank. And, the manifold does result in very clean hose routing while accomodating a longhose primary, bungee back up and inflator as well as dry suit inflator if needed.
Reading between the lines, it is scaleable to two tank sidemount diving and the same approach would work with the addition of another QD hose on the right side.
I will be the first to admit my reaction was exactly the same (great bladder, great harness, who needs the manifold?). But Andrew's reasoning is very compelling and after talking with him at length about it, I'm hesitant to reject it without at least seeing how it works in the real world.
The UTD monkey diving rig is someone intriguing... but the little manifold thing they use is absolutely unnecessary.
They had to have something to justify the cost of a few feet of webbing and handfull of D-rings :-D
SuPrBuGmAn
11-30-2010, 08:45 AM
No argument there regarding it being neccesary. But the underlying concept has some merit and the idea is to allow standard hog/DIR hose routing to maintain commonality with standard backmount hose routing.
From the perspective of how it is currently marketed (monkey diving) it makes sense to stay with standard hose routing as opposed to a single tank with single second stage with perhpas an octo bungeed to the tank. And, the manifold does result in very clean hose routing while accomodating a longhose primary, bungee back up and inflator as well as dry suit inflator if needed.
Reading between the lines, it is scaleable to two tank sidemount diving and the same approach would work with the addition of another QD hose on the right side.
I will be the first to admit my reaction was exactly the same (great bladder, great harness, who needs the manifold?). But Andrew's reasoning is very compelling and after talking with him at length about it, I'm hesitant to reject it without at least seeing how it works in the real world.
Is it not possible(and easy) to run your hoses in a hoglike fashion without the gasblock? Sure, you aren't using standard hose lengths for the backup, but the routing can be the same. It run my hoses just like I did in BM, took a 32" hose for the bungeed second, and a shorter(9" is what I'm currently using) inflator hose, everything else is pretty much run the same.
Gas blocks for SM are not news either, but most people atleast put them around the front where they are accessible. Regardless, its unnecessary and the only benefit with any merit I can find is someone elses wallet getting fatter, which FW aluded to.
DA Aquamaster
11-30-2010, 09:04 AM
The "gas block" is not the issue of concern. Unlike the gas switching blocks I used in commerical diving it is just a manifold with no switching involved and no real need to access it during the dive.
I agree you can run your hoses in the same basic hog manner with a sidemount set up, but each hose runs soley to one tank with no ability to access the gas in either tank with either hose and with the requirement to switch between regs during the dive rather than staying on the long hose for the entire dive.
Again it seems to address the monkey diving concerns that have been raised. This was the original intent of the system when it was recognized that monkey diving sans BC and octo was probably going to eventually result in a fatality. It has the added bonus of allowing a standard hose configuration as well as other surface supply and bailout applications.
The potential to do sidemount differently than is currently the case is just a side effect. Reg switching would not be routinely involved but rather opening and closing the left and right valves would be used to ensure tanks were properly managed and balanced during the dive.
It also simplifies the gas share issues in mixed teams. Gas sharing is the same as with any other standard long hose back mount system with no lack of clarity as to what reg an OOA diver should take.
If the system has a weakness and/or excessive complexity it is in terms of quick disconnects and check valves, so if you're going to bash it without ever seeing it, at least do so on issues of merit rather than just bashing it for exploring a different approach.
SuPrBuGmAn
11-30-2010, 10:24 AM
What did the gas block do to address any concern with monkey diving that couldn't be done easily before? Whats keeping you from running a standard hose configuration without the gas block? The lengths aren't the same, but the routing can be extremely similar, easily.
I'd MUCH rather swap regs than close valves, it'd be just as easy, sure, but it takes less time and in a tight area... its not impossible.
OOA diver always takes whats in the mouth, it ain't difficult. It ain't any different than in BM. If they end up with the 'short' hose, which is typically 30+" if wrapped around the head in a 'standard' BM configuration type way, there's plenty of room to get gas, and swap regs.
I'll bash it because its not necessary, doesn't make anything easier, and its just another expensive marketing ploy.
"monkey diving" is SANS BC. That's the whole concept.
If you use a BC, you are simply sidemount diving with a single or double tanks...
DA Aquamaster
11-30-2010, 11:29 AM
"monkey diving" is SANS BC. That's the whole concept.
If you use a BC, you are simply sidemount diving with a single or double tanks...Exactly. That's the risk that was recognized and the conceptual change intended in using a trim bladder rather than no BC at all. You get 95% of the streamlining but some added benefit in terms of buoyancy and trim control.
Obviously thats a bad thing.
DA Aquamaster
11-30-2010, 11:35 AM
What did the gas block do to address any concern with monkey diving that couldn't be done easily before? Whats keeping you from running a standard hose configuration without the gas block? The lengths aren't the same, but the routing can be extremely similar, easily.
Grab your camera and show me how that works with a single AL 80 mounted on the left side while keeping the hoses clean and close to your body. Not arguing that you can't do it just that the end result may not be as elegant as the concept you seem so opposed to.
I'd MUCH rather swap regs than close valves, it'd be just as easy, sure, but it takes less time and in a tight area... its not impossible. I agree - depending on the hose routing used. You are by the way finally making legitmate comments and critiques.
However, a related issue is that there is nothing even remotely representing a standard sidemount hose routing configuration. In that regard the idea is noteable for moving in a direction that makes a standard configuration more workable.
OOA diver always takes whats in the mouth, it ain't difficult. It ain't any different than in BM. If they end up with the 'short' hose, which is typically 30+" if wrapped around the head in a 'standard' BM configuration type way, there's plenty of room to get gas, and swap regs. How is that better than eliminating the potential to get the short hose and have to sort it out later?
Grab your camera and show me how that works with a single AL 80 mounted on the left side while keeping the hoses clean and close to your body.
I route my hoses just as I do in a configuration with 2 AL80s, and I don't see a streamlining issue. A gas block on my back is simply creating more complexity in a system that is supposed to be about "minimalist standards".
As such, it is simply sidemounting with a single tank... with added complexity for no better reason then to sell stuff.
phillip1
11-30-2010, 11:57 AM
Truth is if you are properly weighted you do NOT need any buoyancy device for diving fresh or saltwater with up to two (even three) AL tanks, be it cave diving or monkey diving.
In my experience all my dives in freshwater with up to three tanks I NEVER use the MSR bag once, I do not need it so I ended up not taking it on any dives unless with more than 3 tanks.
In the ocean I need to add a bit of additional weight to my harness and I am prefect, I do not need any BC device at all and I can float comfortably on the surface and if need be even more "floatness" can be achieved by ditching my tanks and harness, then I am full on floating.
For what I dive I really fail to see the safety issue with not using a BC device, I mean freedivers don't use any BC device of any kind, in spearfishing either, they are all properly weighted and are in the identical ocean situation as a diver in an emergency yet it is not unsafe to be doing that any more than it is to dive with no BC device if you do not need one.
As far as safety an unconscious diver in doubles with a wing type jacket would not be able to float head up at all, he or she would be face down and drown, yet this is not seen as unsafe from a "the BC is also supposed to also be a life vest" point of view, a wing type BC is really dangerous.
As for OW level divers getting into this I have no opinion really but I do think that 99% of entry level OW divers are way overweighted and compensate by using too much air in the BC, these same divers might spend they're whole life diving that way and not ever realize they are using way too much weight.
This whole Monkey diving thing involves actually learning how to be properly weighted, instead of compensating with air in a BC, so it could make much better divers out of a lot of people.
On the other hand I do not deal with OW divers a lot so instructors might have a totally different take on this.
I did however lend my Razor in Honduras to an OW diver and he freaked out and really loved it, he was of the same wight and build than me and he had perfect trim and buoyancy, I used his BM BC and hated it. I am not sure if he was more unsafe in my Razor than in his BC.
This whole Monkey diving thing involves actually learning how to be properly weighted, instead of compensating with air in a BC, so it could make much better divers out of a lot of people.
Apparently that outcome is a concern....
DA Aquamaster
11-30-2010, 12:57 PM
Truth is if you are properly weighted you do NOT need any buoyancy device for diving fresh or saltwater with up to two (even three) AL tanks, be it cave diving or monkey diving.
In my experience all my dives in freshwater with up to three tanks I NEVER use the MSR bag once, I do not need it so I ended up not taking it on any dives unless with more than 3 tanks....No one is arguing the value of proper weighting. I started as a free diver (back when it was called skin diving) and the same weighting approach was then common to scuba diving - essentially neutral at 15', and slightly positive at the surface (with the same being true in scuba with a near empty tank and no air in the bc.) It's unfortunate that has been lost and that too many piss poor instructors immediately add more weight to OW students rather than addressing the underlying issues.
But I am trying to get my head around this - three AL 80s, 231 cu ft of gas and 154 used if dove to two full thirds. That's basically 10 pounds of swing weight for the gas used. Are you claiming to be accomodating that on lung volume alone or are you indicating that there is no need to be neutrally buoyant at the beginning or end of the dive?
phillip1
11-30-2010, 04:33 PM
with 3 AL 80's I am slightly negative at the start of the dive and more or less neutral below 3-4 mtrs at the end. I use no weights in freshwater and have 7mm suit with a 3mm hood. I have done numerous dives this way and it works fine, with two AL 80's I am not negative at all and at the end below 3-4mtrs I am perfectly neutral.
I dont think there is such a big swing weight as 10lbs, but yes lung volume alone is enough for freshwater dives with up to 3 AL80's.
More than that I use a 6L MSR bag and very little air inside it.
SuPrBuGmAn
11-30-2010, 07:04 PM
Not arguing that you can't do it just that the end result may not be as elegant as the concept you seem so opposed to.
Whats elegant about an extra hose, an obnoxious q/d, and a gas block strapped on your back?
http://api.ning.com/files/-Cq7Hjt*-oz0qM82eAzB6g9xqgT3Sxq34LQchJnFo5LckdrrOKKUjofCSBa Yfppq087V*FV6Xzc8z6Xe2YrUGTzlXOOa*J*e/zsys16_800.jpg?width=500
I'm sure you can figure out how to route hoses off a single cylinder cleanly and still have the hoses come around your neck like the BM standard, even if you're just pretending to be smart.
phillip1
11-30-2010, 07:23 PM
when I dive in the ocean it's a single tank with an octopus length hose whatever that is, on an extra reg tucked in a tank band, this is a really simple setup and is perfect for sharing air if need be and very streamlined too
When I dive solo in the ocean a single reg worn with a necklace.
OneBrightGator
11-30-2010, 08:34 PM
While I've never done any monkey diving, I can visualize a single tank regulator with 2 second stages and an inflator hose pretty easily and certainly for less than $1,200. Ridiculous.
One issue that popped into my head is connecting the rig to the tank in water. I imagine it would be a small amount, but wouldn't some water get into the hose which would get into everything downstream, the gas block, LP hoses and 2nd stages?
CaveBuddy95
11-30-2010, 09:04 PM
I think they use a quick feed sort of thingy, from rebreathers, if you need to ad different mix to your loop or for other use (I'm not RB diver!)
DA Aquamaster
12-01-2010, 07:02 AM
While I've never done any monkey diving, I can visualize a single tank regulator with 2 second stages and an inflator hose pretty easily and certainly for less than $1,200. Ridiculous.
One issue that popped into my head is connecting the rig to the tank in water. I imagine it would be a small amount, but wouldn't some water get into the hose which would get into everything downstream, the gas block, LP hoses and 2nd stages?Where did you get the $1200 figure?
phillip1
12-01-2010, 08:28 AM
Ok so we were bored yesterday afternoon with Mat and we tested various configurations as "life jackets"
Now I think the safety issue with monkey diving vs a traditional BC is that in the event of an unconscious diver or needing to float at the surface whatever config you use should also reasonable double as a life jacket at the surface.
here is what I found
In a set of AL80's with a 5lbs SS backplate a 5mm suit and an Apeks wing it is completely impossible for an unconscious diver to be floating head up, without constantly moving around, swimming or balancing on your back you are face down, neutral position is face down in the water. Buddy towing is a hassle and buddy has to constantly maneuver the victim so he does not turn over and drown, not easy and kind of unrealistic if conditions are really rough I imagine (not ideal even in a pool)
With a Seaquest Black Diamond OW wing style BC single AL80, 5mm suit and 7lbs weight, same deal unconscious you are 100% face down, it is much less uncomfortable at the surface and you need to swim and move around less to be face up but still kind of a hassle, neutral position is face down in the water. Same towing hassle although a bit easier to manage due to single tank and slightly less "wing" type design
Regular Sherwood jacket style OW BC single AL80, partially inflated you are ok face up unconscious although you would drown for sure as your head tends to fall in the water no matter what but you are not "forced" face first as in the two above, fully inflated you end up face in the water (unconscious), it is much more comfortable with the jacket BC and you don't need to swim much or move around to stay floating head out of the water, this is the most "life Jacket" style floating for lack of a better description. Towing is pretty easy and not much is needed to keep victim's head out of the water other than paying attention.
Razor with one AL80 and no MSR bag, 6lbs weights and as above 5mm suit, I float feet down head slightly out of the water, unconscious diver would drown as head bobs up and down and is not fully out of the water, but head is not forced underwater as in the two wing type BC's, but still as an unconscious diver you would drown. I tried with just the wetsuit to simulate ditching the gear (obviously an option for all the above) and I can float on my back comfortably without having to force my head out of the water as with the wing type BC's. Towing is super easy, the easiest of all our situations.
I also tried using the MSR bag as a life jacket and it works really well, you loop the bungee around your chest and grab hold and it is just as good as grabbing an airliner seat cushion, never actually tried that but from seeing it demonstrated every time I fly, I am assuming it would.
My point is I fail to see why a properly weighted diver in a Razor with an MSR bag is any less safe than a diver with a OW wing style jacket (really popular now) or a technical diver in doubles.
Yes the regular jacket style BC is safer from a "BC needs to also double as a life jacket" point of view I agree 100%, but nowadays on any given OW boat there are as many or more divers using wing type OW BC's as divers using regular jackets style BC's, and those wing type of BC's from a life jacket point of view are dangerous as you are forced face down unless you swim or move around.
Doubles with a wing force you face down too, yet I have not seen one thread or comment pertaining to this being unsafe, I don't think it is, I am just saying, I think monkey diving, what I do all the time in the ocean, one AL80 and a Razor with no MSR is not any less safe than any other type of configuration.
I don't think a way overweighted OW diver with 4 dives in a jacket style BC is any more unsafe than a properly weighted OW diver with 4 dives in a Razor with an MSR bag.
The whole OW thing is almost always put too much weight on, compensate for the extra weight with more air in the BC and never learn how to actually use the correct amount of weight, so many divers will dive with way too much weight and never even know it.
A BC is NOT to compensate for too much weight nor is it a life jacket.
moteman
12-01-2010, 09:31 AM
Ok, I've been following this thread for some time now. I'm NOT an expert in way. I just began side mount instruction and have a total of two dive sidemount but I am PADI divemaster with >1000 dives and a saltwater tech diver with several +200fsw trimix dives. After looking at the Razor harness and several of it's clones, used with or w/o MSR bags and reading the discussions on tank bouyancy swing and need of positive bouyancy for safety, it seems to me that the ideal bouyancy device for use with these minimal harnesses might be a good old fashion horse collar BC, especially for use when diving big steels with Razor/clone harnesses (doning Nomex now, so let the flaming began).
...it seems to me that the ideal bouyancy device for use with these minimal harnesses might be a good old fashion horse collar BC....
Or a simple OW jacket BCD.
One thing that the AL80 divers seem to miss is that when you are using large steel tanks, you don't have any lead at all, but you still need a big BCD to compensate. I agree fully that you won't need any lead with AL80s...IF...you are in a thin wetsuit, and not too bouyant all by yourself.
Phillip, I was wearing 4 AL80s on that long dive, and was fine in my 7mm Farmer John with no lead, and no air in my BCD, until we got to the deco stop. There I had to hold onto the cave to keep from floating up.
phillip1
12-01-2010, 11:53 AM
I agree with you, at the end of my dives above 3-4mtrs I am slightly positive, when I inhale a lung full I get a bit positive and when I exhale I stay neutral, still very controllable though.
With my 7mm and a 3mm hood I now wear 3lbs in freshwater as I have gained a bit of weight.
OneBrightGator
12-01-2010, 06:05 PM
Where did you get the $1200 figure?
Straight from the UTD website...
http://utdequipment.com/product_info.php?products_id=203
I posted the link in the other Z-harness thread, along with how much it reminded of the Mares HUB.
phillip1
12-01-2010, 06:40 PM
really a truly I think it's a pretty cool system, I think it is way better than any OW rig out there (from my experience with the Razor in OW) it looks like a Razor kind of so I am sure it is really comfortable and fun to dive.
It also has a fully functional BC system too for those who would need it.
DA Aquamaster
12-01-2010, 07:47 PM
Straight from the UTD website...
http://utdequipment.com/product_info.php?products_id=203
I posted the link in the other Z-harness thread, along with how much it reminded of the Mares HUB.Thats the full kit, assuming you don;t already have hoses, etc. The $949 version would be adequate for most divers switching to the system and $499 gets you the harness and bladder if you are using it for tradtional sidemount configuration.
But yes, the whole thing as a package is a bit steep, especially for rectrational diving only.
BC's in general are expensive in the dive industry and the issue is that fully half the "cost" is for liability insurance and the BC maker seems to invariably get sued when a diver drowns. I wonder if that is part of the high purchase price here.
OneBrightGator
12-01-2010, 09:42 PM
Yeah, but the hoses, two 2nd stages and one 1st stage cost money if you bought it years ago or with the Z-system. The system dictates that the regulators would be dedicated to the system. I would not want to be switching around hoses with it like I will for traditional single tank diving.
I don't see how it could be used to sidemount, it doesn't appear to have upper or lower attachment points for traditional sidemounting and the lift would be barely enough under the best circumstances outside of MX.
DA Aquamaster
12-02-2010, 06:19 AM
Yeah, but the hoses, two 2nd stages and one 1st stage cost money if you bought it years ago or with the Z-system. The system dictates that the regulators would be dedicated to the system. I would not want to be switching around hoses with it like I will for traditional single tank diving.
I don't see how it could be used to sidemount, it doesn't appear to have upper or lower attachment points for traditional sidemounting and the lift would be barely enough under the best circumstances outside of MX.No one is arguing the limited application in sidemount (AL 80's etc.) and in fact it is the potential optimiztion for MX applications that create much of the attraction - basically a bogarthian harness with a real live well engineered trim bladder rather than a MSR bladder. That remains true whether or not you also want the hose and manifold concept.
... basically a bogarthian harness with a real live well engineered trim bladder ....
Larry, do you have stock in UDT? :rollguy
OFG-1
12-02-2010, 06:48 AM
Just get a Miller harness and be done with it.
http://www.millerdiving.com/products/harnesses/miller-bell-harness
Just get a Miller harness and be done with it.
http://www.millerdiving.com/products/harnesses/miller-bell-harness
I love this part, "...the harness features an elevated strap with hook up D-ring, positioned in back, about shoulder level. Thus a limp or unconscious diver would be pulled into the bell head first..."
OFG-1
12-02-2010, 07:27 AM
I love this part, "...the harness features an elevated strap with hook up D-ring, positioned in back, about shoulder level. Thus a limp or unconscious diver would be pulled into the bell head first..."
Well, get the one with the backpad and you can screw your MSR bag to it.
http://www.millerdiving.com/products/harnesses/miller-backpack-harness
CaveBuddy95
12-02-2010, 08:09 AM
I don't see the Hogarthian side of this rig. Too many failure point with all the ports and other quick connect.
Hogarthian is as much the simplicity of the rig than the way it is configured. I think so far, a modified MSR 6 or 10 Lt (properly I say :) ) hooked onto a Razor (the real one) topped with the right hose config, BULs on the helmet and primary butt mounted and you've got the most DIR sm rig around.
I've seen it's value specially on mixed team as the hose routing is same as bm divers and offers no surprises on critical OOA moments. Anything in the order of short hose and passing along a tank is, in my mind advanced sm divers diving in very tight cave - no much of Hogarthian going there. Or maybe should I say Bogaerthian..?
:)
DA Aquamaster
12-02-2010, 09:12 AM
Larry, do you have stock in UDT? :rollguyUDT or UTD?
I don't and I'd be surprised if they had publicly traded stock. But I do have a positive regard for a company that has an interest in innovation and has a rational reason for developing the products they develop. The product in question may or may not succeed and it is targeting a niche market at a failry high price point, but I'd like to see the company succeed if it prompts further innovation.
Look at any change and you will find resistance to that change but initial resistance often does not have anything to do with eventualy long term acceptance of the concept. The wing, the octo, the long hose reg, nitrox, trimix are all examples of things that encountered initial resistance bfore becoming more mainstream.
It's way before my time but I would not be surprised if line arrows and cookies were initally seen as a waste of time by the fans of dorf markers and clothes pins.
UDT or UTD?
I don't and I'd be surprised if they had publicly traded stock. But I do have a positive regard for a company that has an interest in innovation and has a rational reason for developing the products they develop. The product in question may or may not succeed and it is targeting a niche market at a failry high price point, but I'd like to see the company succeed if it prompts further innovation.
Look at any change and you will find resistance to that change but initial resistance often does not have anything to do with eventualy long term acceptance of the concept. The wing, the octo, the long hose reg, nitrox, trimix are all examples of things that encountered initial resistance bfore becoming more mainstream.
It's way before my time but I would not be surprised if line arrows and cookies were initally seen as a waste of time by the fans of dorf markers and clothes pins.
Their idea of a "central gas block" is not new or innovative...
http://www.mares.com/product_detail.php?id=291®ion=ALL
It is as unnecessary on a OW BC as it is on a sidemount BC.
OFG-1
12-02-2010, 10:10 AM
UDT or UTD?
How about STD?
How about STD?
Or UTI :roll:
Joe, are you ready to lock this thread yet :rollguy
LiteHedded
12-02-2010, 10:52 AM
Their idea of a "central gas block" is not new or innovative...
http://www.mares.com/product_detail.php?id=291®ion=ALL
It is as unnecessary on a OW BC as it is on a sidemount BC.
I don't think swiping the razor concept is innovative either. charging what they do for the system and the classes is an innovation in itself, but that's about it
MORGAN
12-02-2010, 10:57 AM
Or UTI :roll:
No, that's on the how to clean your p-valve thread.
OneBrightGator
12-03-2010, 09:56 AM
No one is arguing the limited application in sidemount (AL 80's etc.) and in fact it is the potential optimiztion for MX applications that create much of the attraction - basically a bogarthian harness with a real live well engineered trim bladder rather than a MSR bladder. That remains true whether or not you also want the hose and manifold concept.
How about this for half the price...
http://www.zeagle.com/showproduct/1079/Express-Tech/
phillip1
12-03-2010, 12:45 PM
I Agee with Tegg, it feels really free.
i used to free dive a lot and this one tank no BC thing is very much that "free" you are at one with the fish kind of sensation (I know that is a super corny description but it's true).
I almost stopped diving in the ocean altogether due to cave diving, but monkey diving really put the fun back into ocean diving for me, IMHO i think it is just as safe as any other configuration and is definitely not limited to just power snorkeling, it is an efficient, comfortable and super extra fun way to dive OW.
Anyone who is a skeptic should
1-get properly weighted and 2- try it and see for themselves.
Slüdge
12-03-2010, 01:06 PM
I've looked all over the internet. I can't find any of those tanks that weight the same full and empty.
Benderr
12-03-2010, 02:29 PM
I don't see the Hogarthian side of this rig. Too many failure point with all the ports and other quick connect.
Hogarthian is as much the simplicity of the rig than the way it is configured. I think so far, a modified MSR 6 or 10 Lt (properly I say :) ) hooked onto a Razor (the real one) topped with the right hose config, BULs on the helmet and primary butt mounted and you've got the most DIR sm rig around.
I've seen it's value specially on mixed team as the hose routing is same as bm divers and offers no surprises on critical OOA moments. Anything in the order of short hose and passing along a tank is, in my mind advanced sm divers diving in very tight cave - no much of Hogarthian going there. Or maybe should I say Bogaerthian..?
:)
I thought helmet-mounted lights were DIW......
Merlin Rhoda
12-03-2010, 08:04 PM
with 3 AL 80's I am slightly negative at the start of the dive and more or less neutral below 3-4 mtrs at the end. I use no weights in freshwater and have 7mm suit with a 3mm hood. I have done numerous dives this way and it works fine, with two AL 80's I am not negative at all and at the end below 3-4mtrs I am perfectly neutral.
I dont think there is such a big swing weight as 10lbs, but yes lung volume alone is enough for freshwater dives with up to 3 AL80's.
More than that I use a 6L MSR bag and very little air inside it.
Hi Phillip,
I like the razor setup, and by no means am trying to criticize the rig. I am concerned about the change in buoyancy from full tanks to empty tanks when no bladder (msr bag) is used.
Air weighs about 0.0807 lbs per cubic foot. Three full alu80's contain a bit over 18 lbs of air (77cf each). If you plan on exiting with 1/3 remaining in the tanks then that's a buoyancy swing of 12 lbs. Personally I'd like to know that I can use all the air in my tanks in an emergency which means I need to be able to end my dives 18 lbs lighter than I started.
An adult male can pump somewhere around 5 liters or .18 cf of air in and out of their lungs, which corresponds to about 11 lbs of buoyancy. If one needs to shift their buoyancy by a good fraction of this then they aren't going to be breathing very naturally or efficiently.
The numbers don't paint a very good picture of neutral buoyancy at the beginning and end of the dive. Can you help me understand what you're doing differently?
BabyDuck
12-04-2010, 08:15 AM
i think they're swimming pretty constantly. no harm in that or anything & i'm sure they can do that cleaner than i can hover, but that's what i think is going on.
OneBrightGator
12-04-2010, 11:01 AM
Merlin,
Don't attempt to use logic in that argument or get a realistic answer. Sludge and I have been trying for quite some time and have had no luck whatsoever. The truth is that you can't maintain neutral buoyancy throughout a dive without a buoyancy compensator but for whatever reason he, and shockingly, some others on this board, will not agree with that.
phillip1
12-04-2010, 02:56 PM
Yes you can, and with AL tanks you do not need any BC of any kind, with two tanks it is spot on, with three i am a bit negative at the start and a bit positive at the end, but ally not to the point we a BC or additional weight is needed.
again we are talking warm water a 7mm suit and aluminum tanks.
I think that you guys really should check out Steve Bogaerts site and videos.
Really and truly with al tanks (up to three) lung volume alone is enough, if you cannot control you buoyancy using two al 80's without using a BC, I am sorry but your buoyancy control is not very good and you are probably diving somewhat to a lot overweighted but most probably don't even know it since you always rely on a BC to compensate for the extra pounds.
Unless you use huge light canisters which add a lot of weight.
At the start two AL 80's are about 1.5 lbs negative and at the end they a about 2-3 positive if even that since I always have much than a third at the end in each.
I wear a 7mm with a 3mm vest, 2lbs of weight, my light canister is about a pound or so negative and the valves are each about a pound too, so if you factor in the wetsuit volume and hood I am a bit negative at first and pretty much neutral throughout the dive and maybe a tad positive at the end, and with three tanks a bit positive too.
lung volume alone is more than enough to control the buoyancy shift which is really not that much at all.
This is how i set up my harness after a few dives and it works really good, there is only really a 6 lbs buoyancy shift more or less during the dive which lung volume is more than enough to control.
I have never sat down and actually thought about weight ect.. I have tried many different defile and shed as much weight as possible from my harness, i started out to heavy and compensated with the MSR bag at first, diving with 6 lbs,and through trial and error got it down to using 2 lbs, although I did gain weight so I might up that to three.
Lung volume is like having a 10 litre or more MSR bag and really works well, once I was properly weighted I need up never using the MSR bag at all so unless i am diving more than 3 tanks I don't take it.
OneBrightGator
12-04-2010, 04:15 PM
The buoyancy shift is probably manageable, but there is no way to stay neutrally buoyant through an entire single tank dive, let alone with 3 tanks.
Let's not make this personal, since you have not one clue about me and my diving. I've limited my discussion to pure physics, for your sake, let's stick to that. I've been through all of Steve's website. Lung volume is completely dynamic, unless you have some super human ability to breathe out of just the top of your lungs at the beginning of the dive and the bottom at the end. I use lung volume to change buoyancy, more precisely, to start to change buoyancy, but lung volume cannot be used the same way a buoyancy compensator is.
phillip1
12-04-2010, 07:00 PM
I was not talking about single tanks, when i dive single tanks it is in the ocean with 5 lbs of weight and a 5 mm wetsuit, and set up like that i can stay perfectly neutral throughout the dive.
s for double aluminum tanks Steve B dives like that an so do many others, Forrest does too and they have perfect neutral buoyancy throughout the dive, most use lung volume only some like Forrest use a wing and minimal weight.
i am not lying to you, why would I? That is how i dive every time, you can see all the videos on YouTube i posted were i am diving the Razor, other than the shots were i am carrying the 150 w halogen which is super heavy, I do not use the MSR and i am neutral all the time.
When i used to dive BM i used a 5lbs SS backplate, and no weights, i would use a minimal amount of air in my wing at the start of the dive and none at the end, this was with two AL80's and I was only 2 pounds heavier due to the backplate compared to the Razor setup I am diving now, weight wise I was only 2 lbs heavier in that setup than i am diving now in the Razor, and almost did not use any air in the wing.
There are many many people diving the Razor and almost all use lung volume alone for AL tanks, as i said before with three I am slightly negative at the start but i can perfectly control my buoyancy and yes stay neutral using my lungs during the entire dive.
Am sorry if I may have offended you a bit but you did say it was impossible to do with aluminum tanks, steel tanks are another matter, but if you cannot control your buoyancy with two or even three aluminum 80 tanks and rely on a wing to compensate to the point were it actually really seems "impossible to do" without using a wing, then IMHO you are diving overweighted.
Nothing personal but that is my opinion, I am not the best diver nor do I claim to be, but I can say this: it is really really easy to stay neutral during a dive using lung volume only with up to three aluminum tanks.
CaveBuddy95
12-04-2010, 07:24 PM
I back Phil on that one as I dive in this config too. It works for the same conditions (frsh water, wetsuit) I don't use long volume as I am slitly negatively buoyant from start, even without tanks... So I use a 6lt MSR with a proper power inflator+corugated hose and an OPV. It is the streamilnest rig ever. But it only works in Mexico :) :) :)
The best thing to do, for the non-believer(s), is to come over for a Basic sidemount course with Steve B and see for yourselves. I was a non-believer for start but was convinced after day 1. :)
Its the future...
Phillip, nobody is downplaying the importance of neutral buoyancy, or doubting one's ability to weight themselves so that they are neutral. What they have issue with is the fact that air has weight, and if you are neutral at the beginning of a dive, you will be eighteen pounds positive after breathing three aluminum 80s down to a third each. Even if you split the difference perfectly, you will start the dive nine pounds negative and end the dive nine pounds positive. Are your lungs THAT big?
diveongas
12-05-2010, 01:55 AM
I know some readers are tired of me asking you this, but you keep going on and on about it and have never answered the question - you have been talking about two side cylinders and a stage, breathed down to a third. How do you compensate for an eighteen-pound buoyancy shift?
I, for one, never tire of it since it has never been answered and cannot be answered. I just wanna know who sells these freaking majic tanks!
Lung volume control---is he holding his breath for some period of time, or is there some sort of erratic breathing pattern to master?
Merlin Rhoda
12-05-2010, 05:39 AM
I found a little more information on Steve Bogaerts web site in the FAQ section: http://www.gosidemount.com/faq.asp
...I quickly upgraded to a 3l version that gave me just enough lift (6.6lbs) to dive with a single AL80 stage in addition to the AL80 Side Mount tanks.
http://www.gosidemount.com/images/0.gif
I have recently upgraded again to using the MSR Dromedary Hydration Bags instead of the Camelbak’s as they are better made, more rugged and durable and come in a larger range of sizes 2L, 4L, 6L and 10L.
The beauty of not having an integrated BCD is that you can add whatever level of buoyancy is required according to tank size & material, total equipment load, environmental factors, exposure suit type etc.
http://www.gosidemount.com/images/0.gif
I am currently using a 2l for No Mount dives, a 4L for Side Mount single stage dives and a 6L for Side Mount multi stage dives...
This makes more sense - for single stage (3 alu 80's) Steve is diving a 4L bladder (just shy of 9 lbs of lift). If you breath your tanks to thirds then you're compensating for 3 lbs with your lungs (sounds manageable).
I still don't like the case where you end up needing all the gas - now you're struggling with buoyancy in addition to whatever emergency led to using the extra 1/3.
phillip1
12-05-2010, 07:29 AM
At most an empty AL 80 in 4 pounds positive so i am not sure were the extra 6 lbs comes from and how you figure that with more than a third left the tank will be as light as totally empty anyway?
I think you are greatly overexagerating the buoyancy shift, it is definitely not 18 lbs.
I never ended up using the MSR at all so I stopped taking it on dives unless on multi stage dives and still only use it with a minimal amount of air.
as cavebuddy stated, this only works in warm water with aluminum tanks although I bet with a drysuit and steels it would also work well, but that i cannot say for sure I have never even used a drysuit, i think Andrew is diving a Razor with steels and a drysuit.
Also agree with him in that unless you actually try this configuration you really cannot understand how well it works, i came to do the training with steve and was very proficient at using either the nomad or armadillo, both of those i was kind of diving overweighted as most people do, it works that way you have rally good trim and buoyancy control only it does not come close to how well you can control your buoyancy and trim when properly weighted in a Razor or similar type harness.
At the start of the course I was not really sure this Razor thing would really work, until I hit the water and started diving it, it tottaly blew my mind and made a way better diver out of me, Steve is the man!
Sure i could have done all the exploration and dives I have done since using my previous setup it also works but the whole truly minimalistic approach Steve teaches really makes a major difference, you dive feeling totally free of any clutter and it is so much more comfortable.
I think you are greatly overexagerating the buoyancy shift, it is definitely not 18 lbs.
You're right, I had a brain cramp. The air in three 80s weighs eighteen pounds, so breathing them to thirds results in a twelve pound buoyancy shift. Still a lot more than a person's lungs can compensate for.
OneBrightGator
12-05-2010, 01:42 PM
Phillip, I don't know why you're lying to me, and the rest of the forum but what you're saying has nothing to diving ability. What you are saying violates the laws of nature. You are saying that a loss of matter does not result in a loss of weight. Physically impossible.
Diving a few pounds overweighted without a BC is certainly doable, but I for one see no reason to do so but that's not really what you're advocating even. What you're advocating is untruthful and dangerous. Air weighs .07353 lbs./cu. ft., so an AL80 (77 cu. ft.) is 5.66 lbs. heavier full than empty so to be neutral at the end of dive with 3 AL80s you will be 17 lbs. heavy at the beginning of the dive. It is not possible to manage 17 lbs. overweighted. I highly suspect you are splitting the difference. Being 8.5 lbs. heavy at the beginning of a dive would be tough. Being close to 8.5 lbs. light at the end of a dive that put you at the bottom of all of your tanks is beyond dangerous.
Your discussion on steel tanks is mind-boggling. The material of the tank has nothing to do with its buoyancy shift. NOTHING. It's almost comical, because lots of people are diving steel tanks with no real buoyancy compensator and they truly are staying neutral the entire dive. They are using a drysuit to compensate for buoyancy shift.
Bobby
12-05-2010, 03:21 PM
Well I guess I will wade in here. Monkey diving is simple; throw on a weight belt with enough led for whatever exposure protection used, add a d-ring to clip a stage with a long enough second stage hose, and go dive in OW. Lung volume if properly weighted is enough to handle the buoyancy swing. Something for simple, fun, & shallow diving without going into deco.
AL 80's without a BC is also simple. When diving 1/3's there is enough gas left in the cylinders to keep from becoming overly buoyant. If using the last third of gas this should be considered and emergency situation. Breath the stage down to zip and discard, breath one of the sm cylinders down to zip and discard, breath the last cylinder down & hopefully get out of the system.
As far as how to stay nuetral, it is using breath control. At the start of the dive keep the lungs full, breath out and immediately breath in again. In the middle of the dive keep lungs half full, breath out, breath in, and exhale half the lung volume. At the end of the dive keep lung volume low, breath in, and immediately breath out. A couple of second pause at the desired lung volume keeps the diver nuetral.
When working day boats I would often dive down to unhook a wreck just carrying an AL80 in one hand. I don't see the need to over complicate things by putting manifolds and switching blocks into a working simple system. Without a wet suit I am a little too negative, with an AL80 to be truly nuetral. With a 3mm wet suit lung volume works fine and with anything thicker I need a little lead. With the cylinder down to a few hundred psi lung volume can be used to maintain a 20 foot stop. If someone hits me with an OOA while monkey diving I will hand them my cylinder and do a free ascent to the surface. I would not want to bother figuring out if they know how to buddy breath since that is a skill too many divers don't have today.
Bobby
timle
12-05-2010, 03:46 PM
Yeah OW is a totally different situation. If you are slightly negative, fin down a bit; slightly positive, fin up a bit. Silty cave is a different story and managing a 12lbs shift (planned) and potential 18lbs (emergency) with your lungs - and claiming to be neutral the entire dive is laughable. And as someone else already pointed out Steve Bogaerts is using something to offset the shift is buoyancy and you can clearly see him let air out in the following video about 8 seconds in.
http://www.youtube.com/watch?v=8ahQYqho7w4
phillip1
12-05-2010, 03:51 PM
Damn man! you caught me! Diving the Razor with no MSR only works in the movies with special effects, i never done that in real life, only in the movies!
Now I can't sound cool on the message board anymore. Lol...
Let's not make any accusations here. Diving conditions are very different in Florida, and the tropics. In Florida depth doesn't stay as constant as it does in Mexico, and in the D.R. Also haloclines are rare if FL. That makes a big difference in buoyancy requirements.
Whether Phillip understands what you are talking about involving weight swing, he still can make a dive without a BC. I have met him, and I can assure he is an honest person.
Phillip, I don't know why you're lying to me, and the rest of the forum but what you're saying has nothing to diving ability. What you are saying violates the laws of nature. You are saying that a loss of matter does not result in a loss of weight. Physically impossible.
Diving a few pounds overweighted without a BC is certainly doable, but I for one see no reason to do so but that's not really what you're advocating even. What you're advocating is untruthful and dangerous. Air weighs .07353 lbs./cu. ft., so an AL80 (77 cu. ft.) is 5.66 lbs. heavier full than empty so to be neutral at the end of dive with 3 AL80s you will be 17 lbs. heavy at the beginning of the dive. It is not possible to manage 17 lbs. overweighted. I highly suspect you are splitting the difference. Being 8.5 lbs. heavy at the beginning of a dive would be tough. Being close to 8.5 lbs. light at the end of a dive that put you at the bottom of all of your tanks is beyond dangerous.
Your discussion on steel tanks is mind-boggling. The material of the tank has nothing to do with its buoyancy shift. NOTHING. It's almost comical, because lots of people are diving steel tanks with no real buoyancy compensator and they truly are staying neutral the entire dive. They are using a drysuit to compensate for buoyancy shift.
Slüdge
12-05-2010, 04:21 PM
Steve Bogaerts is using something to offset the shift is buoyancy and you can clearly see him let air out in the following video about 8 seconds in.
Looks like an MSR bag at the small of his back.
Steve B. uses an MSR bag, no one denys that. He is the one that came up with the idea.
FWIW, there were a lot of dives made with no BCD of any kind back in the '50s, and early '60s because they just didn't exist yet. We exhaled, and kicked like hell to get down enough for the wetsuit to compress. Another method was to use a "drop off" weight to get to depth, then leave it there. You picked them up later, so you could stay on the deco stop. Of course deco was pretty short, since we were only diving singles back then.
phillip1
12-05-2010, 05:59 PM
I swear it works, I mean at first i would bring my MSR bag on all dives but ended up never using it so i dont bring it unless i am either diving with more than three tanks (al) or carrying a heavy video light canister.
actually Steve also dives on lung volume alone with two tanks.
Anyway i think that weight wise i am pretty much the same as in BM doubles, but BM doubles is not different so it would not even be up for question wether or not i need a BC, in BM I did use a wing but with almost no air in it at all, and in BM I was only 2 lbs heavier than I dive now.
I think the main thing here is that unless you actually try and dive a Razor type setup you really cannot have any idea of how it would feel or work, unless you are a CDG type and kind of know this type of harness setup etc..
To the average diver (no I do not mean that in a derogatory way) the Razor may seem really weird and appear to be so different that it is hard to envison it working, but believe me it does.
I can't just be content to dive one way and have blinders on ignoring the way other people dive, I feel compeled to try out every different configuration, i talk to people see what they dive and why and instead of needlessly analyzing things and then formulating an opinion without ever even trying that perticular configuration, I try it and see how it works out for me.
that is how i ended up meeting Steve and deciding to try his Razor.
i have tried many setups, not just once or twice but to the point were I became proficient in each and my favorite setup so far is the Razor by far, i live and dive in the DR and Mexico were this setup works much better than any BM configuration for me, i can dive any cave or any OW reef or wreck, from huge massive caves were the walls fall out of view, to caves so tight I need to remove tanks just to squeeze through, the Razor allows me flexibillity and comfort like no BM system ever could, (yes i could also do that with a Nomad or Armadillo but they are both a bit bulkier though IMHO) that is why I dive the Razor, if someone comes up with something even better I wil be the first one to adopt it if it works better for me.
Oh I forgot to mention it is way more fun too, that is also a very important advantage for me too.
Slüdge
12-05-2010, 08:25 PM
Where's Ron Bear when you need him?
OneBrightGator
12-05-2010, 09:06 PM
As far as how to stay nuetral, it is using breath control. At the start of the dive keep the lungs full, breath out and immediately breath in again. In the middle of the dive keep lungs half full, breath out, breath in, and exhale half the lung volume. At the end of the dive keep lung volume low, breath in, and immediately breath out. A couple of second pause at the desired lung volume keeps the diver neutral.
Bobby, I don't know you, but I've always found you to be reasonable, logical and helpful on the forums, but this statement is moronically comical. The "stuff" would barely have to have to get near a fan, just a sniff of it would throw that right out the window. Beyond that... Why? That sounds like a great way to turn a decent dive into a task-loaded nightmare all to avoid carrying around a tiny bag.
Let's not make any accusations here. Diving conditions are very different in Florida, and the tropics. In Florida depth doesn't stay as constant as it does in Mexico, and in the D.R. Also haloclines are rare if FL. That makes a big difference in buoyancy requirements.
Let me get this straight... wetsuit compression, 3mm wetsuit compression at that... and the difference in the buoyancy characteristics in fresh and salt water compensate for an 18 lb. weight shift? Especially when that all reverses during ascent...
Right.
I swear it works, I mean at first i would bring my MSR bag on all dives but ended up never using it so i dont bring it unless i am either diving with more than three tanks (al) or carrying a heavy video light canister.
actually Steve also dives on lung volume alone with two tanks.
Anyway i think that weight wise i am pretty much the same as in BM doubles, but BM doubles is not different so it would not even be up for question wether or not i need a BC, in BM I did use a wing but with almost no air in it at all, and in BM I was only 2 lbs heavier than I dive now.
I think the main thing here is that unless you actually try and dive a Razor type setup you really cannot have any idea of how it would feel or work, unless you are a CDG type and kind of know this type of harness setup etc..
To the average diver (no I do not mean that in a derogatory way) the Razor may seem really weird and appear to be so different that it is hard to envison it working, but believe me it does.
I can't just be content to dive one way and have blinders on ignoring the way other people dive, I feel compeled to try out every different configuration, i talk to people see what they dive and why and instead of needlessly analyzing things and then formulating an opinion without ever even trying that perticular configuration, I try it and see how it works out for me.
that is how i ended up meeting Steve and deciding to try his Razor.
i have tried many setups, not just once or twice but to the point were I became proficient in each and my favorite setup so far is the Razor by far, i live and dive in the DR and Mexico were this setup works much better than any BM configuration for me, i can dive any cave or any OW reef or wreck, from huge massive caves were the walls fall out of view, to caves so tight I need to remove tanks just to squeeze through, the Razor allows me flexibillity and comfort like no BM system ever could, (yes i could also do that with a Nomad or Armadillo but they are both a bit bulkier though IMHO) that is why I dive the Razor, if someone comes up with something even better I wil be the first one to adopt it if it works better for me.
Oh I forgot to mention it is way more fun too, that is also a very important advantage for me too.
I have all the hardware and webbing ready to go, I can't wait to see how a couple feet of webbing and some D-rings automatically compensate for up to 18 lbs. of buoyancy shift.
:blackbar2
Bobby
12-06-2010, 06:10 AM
Bobby, I don't know you, but I've always found you to be reasonable, logical and helpful on the forums, but this statement is moronically comical. The "stuff" would barely have to have to get near a fan, just a sniff of it would throw that right out the window. Beyond that... Why? That sounds like a great way to turn a decent dive into a task-loaded nightmare all to avoid carrying around a tiny bag.
I don't know you either; your posts have me thinking you are new to diving (10 years or less) and young. I don't mean that as an insult, newer divers seem to be more absolute. Calling my statement "moronically comical" is immature. I suggest you back away from the key board and go diving, with an AL 80, & work with weighting until you don't need to put any air in your bc. Cave divers were diving with double steels and no bc, not something that should be done today but it was possible. I have dove with two AL 80's and know a bc is not needed. Might I suggest having some personal experience before you call people out so strongly either on a board or in person.
Bobby
Bobby, I don't know you, but I've always found you to be reasonable, logical and helpful on the forums, but this statement is moronically comical. The "stuff" would barely have to have to get near a fan, just a sniff of it would throw that right out the window. Beyond that... Why? That sounds like a great way to turn a decent dive into a task-loaded nightmare all to avoid carrying around a tiny bag....
...I have all the hardware and webbing ready to go, I can't wait to see how a couple feet of webbing and some D-rings automatically compensate for up to 18 lbs. of buoyancy shift.
:blackbar2
Check your PMs.
Also check back through this thread (post 122), you only get 18 lb swing, if you breathe the tanks empty.
:smt059Thank you Forrest.
DA Aquamaster
12-06-2010, 11:39 AM
...check back through this thread (post 122), you only get 18 lb swing, if you breathe the tanks empty.
Right, as I pointed out a few pages ago when I asked Phillip about this, I pointed out that the swing is only 12 pounds if 2/3rds of the volume is used.
Now, 18 pounds or 12 pounds, it makes no difference as the average person can manage about a 6 pound swing on lung volume alone and still achieve neutral buoyancy.
----
Bobby is mentioning modifying where you hold the gas during various portions of the dive in order to take advantage of inertia and shifting between negative and positive buoyancy to essentially cycle around a neutral point. This can work with swing weights slightly in excess of 6 pounds, but it works by holidng excess air in the lungs longer to start a rise early in the dive, and eventually holding he exhale longer than normal to start a descent and in both cases using inertia to sneak in the other half of the respiration cycle. That's not the same as being neutral with a normal breathing pattern. Most obviously, it is a lot less efficient in terms of gas transfer and gas consumption during a significant portion of the dive. In effect you can do it with the 8 pound gas shift you'd find diving double AL 80s to thirds, but the cost in gas consumption is not really worth it. In practice to make it workable you fudge a bit by planing up or down slightly while swimming. Again it works but is's not true neutral buoyancy.
------
Forrest is talking about using wet suit compression to control where you are neutral. This is a long time standard in free diving where you weight your self so the suit is neutral at 15'-30' so that the diver is a) neutral to slightly negatively buoyant at deeper depths to allow the diver to descend with minimal effort and b) be slightly posive at the surface to allow the diver to rest on the surface. Forrest is also talking about using drop weights that can be clipped on at the end of the dive to offset the weight of the gas used during the dive. That again is not maintaining neutral buoyancy using lung volume alone to offset swing weight of the gas.
-----
At some point you have to ask what is the more elegant solution:
1) Using a grossly modified breathing pattenr and planing to stay "neutral",
2) Using drop weights and wet suit conmpression to offset the weight of the gas lost, or
3) Just using a BC of some type.
------
In any case, claiming to compensate for 12 pounds of swing weight on lung volume alone is BS or at least suggests the diver does not understand or is not explaining what is really going on.
At some point you have to ask what is the more elegant solution:
1) Using a grossly modified breathing pattenr and planing to stay "neutral",
2) Using drop weights and wet suit conmpression to offset the weight of the gas lost, or
3) Just using a BC of some type.
------
In any case, claiming to compensate for 12 pounds of swing weight on lung volume alone is BS or at least suggests the diver does not understand or is not explaining what is really going on.
FWIW, I go for #3, but diving with no BC is *possible*.
At some point you have to ask what is the more elegant solution:
1) Using a grossly modified breathing pattenr and planing to stay "neutral",
2) Using drop weights and wet suit conmpression to offset the weight of the gas lost, or
3) Just using a BC of some type.
Anytime you want to go for a dive in OW and see the "grossly modified breathing pattern" to stay neutral, you let me know...
Apparently, you would be surprised at how UNMODIFIED the breathing pattern really is...
OneBrightGator
12-06-2010, 05:20 PM
I don't know you either; your posts have me thinking you are new to diving (10 years or less) and young. I don't mean that as an insult, newer divers seem to be more absolute. Calling my statement "moronically comical" is immature. I suggest you back away from the key board and go diving, with an AL 80, & work with weighting until you don't need to put any air in your bc. Cave divers were diving with double steels and no bc, not something that should be done today but it was possible. I have dove with two AL 80's and know a bc is not needed. Might I suggest having some personal experience before you call people out so strongly either on a board or in person.
Bobby
Interesting... I comment on your idea and you comment on my experience rather than fortifying your position and I'm the immature one?
Right.
Also check back through this thread (post 122), you only get 18 lb swing, if you breathe the tanks empty.
Isn't it even more critical that you have the ability to stay neutral when your tanks are empty: after a significant incident? You are literally setting yourself up for disaster, you survive a major gas loss only to be fighting your buoyancy. For what?
FWIW, I go for #3, but diving with no BC is *possible*.
As do I. I never said it was impossible to dive without a BC, but that it was impossible to be neutrally buoyant at the beginning and end of a dive without one.
Bobby
12-06-2010, 05:48 PM
Right, as I pointed out a few pages ago when I asked Phillip about this, I pointed out that the swing is only 12 pounds if 2/3rds of the volume is used.
Now, 18 pounds or 12 pounds, it makes no difference as the average person can manage about a 6 pound swing on lung volume alone and still achieve neutral buoyancy.
----
Bobby is mentioning modifying where you hold the gas during various portions of the dive in order to take advantage of inertia and shifting between negative and positive buoyancy to essentially cycle around a neutral point. This can work with swing weights slightly in excess of 6 pounds, but it works by holidng excess air in the lungs longer to start a rise early in the dive, and eventually holding he exhale longer than normal to start a descent and in both cases using inertia to sneak in the other half of the respiration cycle. That's not the same as being neutral with a normal breathing pattern. Most obviously, it is a lot less efficient in terms of gas transfer and gas consumption during a significant portion of the dive. In effect you can do it with the 8 pound gas shift you'd find diving double AL 80s to thirds, but the cost in gas consumption is not really worth it. In practice to make it workable you fudge a bit by planing up or down slightly while swimming. Again it works but is's not true neutral buoyancy.
Larry,
How much experience do you have diving an AL 80 without a BC? How much diving two AL 80's without BC? How much experience cave diving, two AL 80's, & without a BC? As I said in my first post don't have experience adding a stage but have dove the others. Probably not 10% as much as Steve B. but enough to know it can be done. Without the experience of adding the stage it seems to me that it would be work but again I don't have the experience. I have found when diving double AL 80's without a wing my RMV is lower than dry, with a wing, and steel cylinders.
Since you are getting technical about truly nuetral buoyancy lets get it straight. If you are breathing on OC then you are not truly nuetral. When I am completely motionless in the water I rise and fall with the breathing. When on CCR truly nuetral buoyancy is only achieved within inches and quickly goes negative as O2 is metabolized. Fin angle adjustments are required to maintain depth until O2 is injected into the loop to replace what has been consumed. Anyone with buoyancy control on OC is managing their breathing. Diving with bc & dry actually makes the margin of buoyancy control smaller because there is a larger volume of air in different chambers. The additional air will expand or contract with depth changes and throw buoyancy off sooner.
It is interesting that the people that seem to have little to no experience, I may be wrong in the assumption, are voicing such strong beliefs that it can't be done. Calling people liars and claims of BS are rather strong, if it is the case that these people have not found out through their own actual experience.
Bobby
Bobby
12-06-2010, 06:03 PM
Interesting... I comment on your idea and you comment on my experience rather than fortifying your position and I'm the immature one?
Right.
Uh, no you are not right. I did not state an idea, I stated experience. There is no need to "fortify" because it was not a position it was experience. I also restated the experience to help clarify my words as well as offered a course of action that you might take to gain your own experience and find out if your own position is in fact correct.
I don't know you either; your posts have me thinking you are new to diving (10 years or less) and young. I don't mean that as an insult, newer divers seem to be more absolute. Calling my statement "moronically comical" is immature. I suggest you back away from the key board and go diving, with an AL 80, & work with weighting until you don't need to put any air in your bc. Cave divers were diving with double steels and no bc, not something that should be done today but it was possible. I have dove with two AL 80's and know a bc is not needed. Might I suggest having some personal experience before you call people out so strongly either on a board or in person.
Isn't it even more critical that you have the ability to stay neutral when your tanks are empty: after a significant incident? You are literally setting yourself up for disaster, you survive a major gas loss only to be fighting your buoyancy. For what?
Already answered with my first post but I will throw it out again. No need to carry empty cylinders they don't do any good. If going past thirds then there is a problem, simple answer is to use up a cylinder completely and get rid of it. Positive buoyancy issue resolved and hopefully the last cylinder gets you out of the system. This is no different than stage diving with steels and an AL 80, with the one detail that most steels are still negative or zero when empty so no need to pitch them, there are a few that are positive and if that is the case then pitch them as well.
As do I. I never said it was impossible to dive without a BC, but that it was impossible to be neutrally buoyant at the beginning and end of a dive without one.
Again as I stated it is possible with breath control and actually is not that difficult. As I have also stated I don't have experience with three AL 80's. One and two I do and it is very simple to handle, unless of course we are talking about truly nuetral then the case is that one can't breath if they wish to remain in that state.
Bobby
As do I. I never said it was impossible to dive without a BC, but that it was impossible to be neutrally buoyant at the beginning and end of a dive without one.
Ben, I offer you the same invite that I posted for Larry...
SuPrBuGmAn
12-06-2010, 06:07 PM
Ben, I offer you the same invite that I posted for Larry...
Where's my offer, you don't even have to prove anything... I just wanna dive.
OneBrightGator
12-06-2010, 06:08 PM
I am currently using a 2l for No Mount dives, a 4L for Side Mount single stage dives and a 6L for Side Mount multi stage dives.
http://www.gosidemount.com/faq.asp#nr03
Slüdge
12-06-2010, 06:28 PM
"What course do I need to take that will teach me how to defy the laws of physics?" - Ron Bear
Okay, seriously, I'm not saying that nobody can do it; I just want someone to come out and say they can do it. Who will publicly state that they can use their lungs for neutral buoyancy, both before and after a 12-pound buoyancy shift.
If you can do it, say so.
phillip1
12-06-2010, 06:41 PM
Why are we even arguing about this with people who evidently have NEVER tried this type of configuration? I mean get weighted properly, get your harness and stuff set up right and try it out, it is super easy to dive, a bit more committing as in a lot more futzing around with the harness to get it set up right, as opposed to a backplate and wing.
Once set up right, I think you will be pleasantly surprised.
I find it so utterly useless to sit around analyzing this setup vs that setup, (all things up for consideration being as safe of course) I just jump in the water and try it out, THEN I formulate an opinion about that particular setup.
Again this all boils down to the average BM diver who views SM as kind of outside the norm, and then they see people diving a Razor type harness with little MSR bags or no BC device at all and that is waaaaaay out of the norm for them, and they formulate an opinion without ever even trying it.
That is the kind of attitude that will keep you from evolving and trying out new things that may or may not work even better and make your diving safer and more fun, not to mention the multitude of really cool caves that you just will never dive if you only BM with blinders on.
phillip1
12-06-2010, 06:43 PM
"What course do I need to take that will teach me how to defy the laws of physics?" - Ron Bear
Okay, seriously, I'm not saying that nobody can do it; I just want someone to come out and say they can do it. Who will publicly state that they can use their lungs for neutral buoyancy, both before and after a 12-pound buoyancy shift.
If you can do it, say so.
I can do it, I do it on lung volume alone with NO BC device of any kind with up to 3 AL 80's.
I do it on every single dive I do here that requires a stage tank.
I have never thought of the buoyancy shift until now, but I have done it on all my dives with NO BC DEVICE OF ANY KIND, since I bought a Razor from Steve and did the course with him a few years back, been diving like that ever since.
Thomas can also do it
Xenia
12-06-2010, 07:27 PM
Is this what you guys have been talking about: http://www.wired.com/images_blogs/photos/uncategorized/2008/01/14/monkey300.jpg
Oh well, knowing Bobby I have to say he is not at all moronically comical... Now comically moronic he is a little bit... but he definitely has no sense of humor! :roll:
OneBrightGator
12-06-2010, 08:39 PM
Ben, I offer you the same invite that I posted for Larry...
Where and when? :)
Maybe if you answer my PM first...
jj1987
12-06-2010, 11:34 PM
Ben, I offer you the same invite that I posted for Larry...
I call BS on you. Can I pick the dive spot we meet at? You know which one I want you to prove me wrong at :)
DA Aquamaster
12-07-2010, 05:51 AM
Larry,
How much experience do you have diving an AL 80 without a BC? How much diving two AL 80's without BC? How much experience cave diving, two AL 80's, & without a BC? As I said in my first post don't have experience adding a stage but have dove the others. Probably not 10% as much as Steve B. but enough to know it can be done. Without the experience of adding the stage it seems to me that it would be work but again I don't have the experience. I have found when diving double AL 80's without a wing my RMV is lower than dry, with a wing, and steel cylinders.
Since you are getting technical about truly nuetral buoyancy lets get it straight. If you are breathing on OC then you are not truly nuetral. When I am completely motionless in the water I rise and fall with the breathing. When on CCR truly nuetral buoyancy is only achieved within inches and quickly goes negative as O2 is metabolized. Fin angle adjustments are required to maintain depth until O2 is injected into the loop to replace what has been consumed. Anyone with buoyancy control on OC is managing their breathing. Diving with bc & dry actually makes the margin of buoyancy control smaller because there is a larger volume of air in different chambers. The additional air will expand or contract with depth changes and throw buoyancy off sooner.
It is interesting that the people that seem to have little to no experience, I may be wrong in the assumption, are voicing such strong beliefs that it can't be done. Calling people liars and claims of BS are rather strong, if it is the case that these people have not found out through their own actual experience.
BobbyI like you nbobby so I'll dispense with the polite **** You, but yes, I have lots of experience diving single and double 80's as well as double Steel 72's without a BC. Vintage diving is the "other" niche type of diving I do and I've been ding it for almost 25 years.
Having that experience I know very clearly that I do not want to dive double AL 80s in a cave absent a BC for exactly the reason we are about to discuss.
You are exactly right that you are never truly neutral on OC as you are siomply averaging around the neutral point. That is clear in my post. The point you;ve missed is that at any point in the dive that nuetral point has to occur within the 6 pound range of buoyancy control you have on your lung volume alone. At any time that neutral point lies outside that sweet spot, then you have to use some other means of maintaining your position in the water column such as planing slightly up or down relying on drop weights or a change in depth and wet suit compression (with is depth and cave profile dependent).
Anyone suggesting they can manage more than 6 pounds of weight shift on lung volume alone either has enormous lungs, or is spouting BS, due to either ignorance or a tendency to play fast and loose with the laws of physics (ie. the truth). You decide which.
Bobby
12-07-2010, 07:15 AM
I like you nbobby so I'll dispense with the polite **** You. snipp
Larry,
I like you as well so I will give you advice from experience. There is no need to go there, I have done it and regretted it. I have maintained civil and respectful conversation.
but yes, I have lots of experience diving single and double 80's as well as double Steel 72's without a BC. Vintage diving is the "other" niche type of diving I do and I've been ding it for almost 25 years.
Having that experience I know very clearly that I do not want to dive double AL 80s in a cave absent a BC for exactly the reason we are about to discuss.
You are exactly right that you are never truly neutral on OC as you are siomply averaging around the neutral point. That is clear in my post. The point you;ve missed is that at any point in the dive that nuetral point has to occur within the 6 pound range of buoyancy control you have on your lung volume alone. At any time that neutral point lies outside that sweet spot, then you have to use some other means of maintaining your position in the water column such as planing slightly up or down relying on drop weights or a change in depth and wet suit compression (with is depth and cave profile dependent).
Anyone suggesting they can manage more than 6 pounds of weight shift on lung volume alone either has enormous lungs, or is spouting BS, due to either ignorance or a tendency to play fast and loose with the laws of physics (ie. the truth). You decide which.
You got me, I must be full of BS & breaking the laws of physics. I mean there is no way that anyone can dive double AL 80’s when there is a buoyancy shift of 5.8 pounds from completely full to completely empty in one cylinder…. Oh wait I seem to recall saying that a single AL 80 could be dove comfortably from full down to a few hundred psi.
Anyone suggesting they can manage more than 6 pounds of weight shift on lung volume alone either has enormous lungs, or is spouting BS, due to either ignorance or a tendency to play fast and loose with the laws of physics (ie. the truth). You decide which.
But wait we are talking about double AL 80’s are we not? Actually we are talking about diving them in a cave to be specific. Diving to thirds (if we have completely filled cylinders at the start and dive all the way down to full thirds) we are talking about a buoyancy shift of 7.66 pounds. Completely impossible I know.
Yep I guess I am diving with ignorance and playing fast & loose with the truth. You got me.
Bobby
I posted this in the manifold thread, and I guess it needs to go here as well!
Alright, everyone play nice! It is ok to have differences of opinion, but we don't need to call one another names.
I have already threatened to ban one member for name calling, and it can apply to others as well.
Everyone read rule #6 again...
phillip1
12-07-2010, 07:41 AM
I have never thought of or even calculated the buoyancy shift, I got trained with Steve when I bought the Razor and through trial and error and a lot of diving ended up diving as I am now.
As I mentioned previously I noted that with up to three AL 80's I never used the MSR so I just don't take it on dives were I don't need it (I thought the whole cave diving concept was to leave unnecessary stuff at home).
The funny thing in this thread is that in BM doubles (AL tanks) I was almost exactly the same weight, only 2lbs heavier due to the SS backplate, and in BM I used only a very minimal amount of air in my wing at first as I was diving a 5mm suit, then I got sick of being cold all the time and I bought a 7mm suit and I would dive with no air in my wing at all and also used lung volume alone, I considered taking the wing off at the time but was advised not too, and being a bit lazy and seeing no effect of having a wing empty I just left it on.
It was pretty much the same as now, a bit negative at the start of the dive but all 100% controllable through lung volume alone, I could hover and stay neutral at all times as I do now, only I looked "normal" I guess being in BM and all.
The only true difference between the Razor and my BM setup buoyancy wise is that BM is the norm and that would not seem impossible but totally normal, however when you see a guy in a Razor with no BC device now THAT looks impossible and way out there to some people, even though it is (in my case) almost exactly the same weight and buoyancy shift just a different configuration.
However I want to make something clear, it is through disagreements and discussions like this, right or wrong, were each person defends his or her position on why one way is better than the other etc.. that one can learn either new ways of diving and doing things or that the way they dive and do things is in fact actually better.
I think this is always a positive thing, hey for all I know I might even end up diving BM steels when I visit FL, I will definitely give it a try that since I never dove steels or caves with a lot of flow, I doubt I will like it but I also doubted the Razor would work as well as it does.
Keep an open mind, you never know what you could be missing.
Bobby
12-07-2010, 07:56 AM
Phillip,
You are right that discussion of views and thoughts moves us forward. When you get to FL you will find that diving steels in flow systems is better. At the entrance is usually the strongest flow and being considerably negative helps get you into the system. It is normally a pull and pull situation until you get into the cave and can hide from the flow. A wet suit is OK for one dive but usually makes two in a day not so fun. Easier during the summer compared to winter when you can warm up the dry suit and yourself between dives. I am a cold blooded woosie so I dive dry all the time now.
Bobby
DA Aquamaster
12-07-2010, 08:13 AM
But wait we are talking about double AL 80’s are we not? Actually we are talking about diving them in a cave to be specific. Diving to thirds (if we have completely filled cylinders at the start and dive all the way down to full thirds) we are talking about a buoyancy shift of 7.66 pounds. Completely impossible I know.
Yep I guess I am diving with ignorance and playing fast & loose with the truth. You got me. Bobby no one is arguing about the feasibility of this with a single AL 80 or any other single tank with a swing weight of less than 6 pounds.
No one is also arguing with doing it when the swing weight of the gas actually used is less than 6 pounds.
7.66 pounds is on the edge and we may not be disagreeing at all when we get past theoretical numbers. For example, divng to "thirds" on double AL 80s will will work just fine provided you are actually diving a bit short of using an actual full two thirds. I'd argue thaty is normally the case for a prudent diver. In my case, when I turn a dive on "thirds" as I won't actually use a full third on penetration if it will REALLY really take a full third for me to exit. If that's the case I'll turn a 200-300 psi early or have extra gas along for the ride.
Similarly, if a diver has 2900 in the AL 80's (or 3200 for that matter) they will round down to 2700, 3000 etc as needed to get even thirds and in effect dive less than 2/3rds of the tank with gas left over that does not end up having to be conmpensated for in the swing weight.
In the real world, I'm willing to bet your swing weight is a lot closer to the 6 pound figure. And it's also possible you have slightly larger than average lung volume.
The point is that when anyone comes on line and claims they can accommodate the swing weight on two AL 80s plus an AL 80 stage on lung volume alone (11.49 pounds of swing weight using your own numbers) is pure BS due to either ignorance or chest pounding. As an extension of that, anyone attempting to defend someone making such a BS statement, no matter how well intentioned runs the risk of getting some of that BS splattered on them.
I know you know your **** Bobby, that's not in question, but it is none the less offensive when my intelligence and experience gets called into question when just pointing out what is pure 100% unadulterated BS. Have you considered what happens if someone takes Philip seriosusly and actually tries this?
phillip1
12-07-2010, 08:27 AM
Bobby no one is arguing about the feasibility of this with a single AL 80 or any other single tank with a swing weight of less than 6 pounds.
No one is also arguing with doing it when the swing weight of the gas actually used is less than 6 pounds.
7.66 pounds is on the edge and we may not be disagreeing at all when we get past theoretical numbers. For example, divng to "thirds" on double AL 80s will will work just fine provided you are actually diving a bit short of using an actual full two thirds. I'd argue thaty is normally the case for a prudent diver. In my case, when I turn a dive on "thirds" as I won't actually use a full third on penetration if it will REALLY really take a full third for me to exit. If that's the case I'll turn a 200-300 psi early or have extra gas along for the ride.
Similarly, if a diver has 2900 in the AL 80's (or 3200 for that matter) they will round down to 2700, 3000 etc as needed to get even thirds and in effect dive less than 2/3rds of the tank with gas left over that does not end up having to be conmpensated for in the swing weight.
In the real world, I'm willing to bet your swing weight is a lot closer to the 6 pound figure. And it's also possible you have slightly larger than average lung volume.
The point is that when anyone comes on line and claims they can accommodate the swing weight on two AL 80s plus an AL 80 stage on lung volume alone (11.49 pounds of swing weight using your own numbers) is pure BS due to either ignorance or chest pounding. As an extension of that, anyone attempting to defend someone making such a BS statement, no matter how well intentioned runs the risk of getting some of that BS splattered on them.
I know you know your **** Bobby, that's not in question, but it is none the less offensive when my intelligence and experience gets called into question when just pointing out what is pure 100% unadulterated BS. Have you considered what happens if someone takes Philip seriosusly and actually tries this?
I am full of **** I guess, oh well that's really too bad I thought I was cool.
DA Aquamaster
12-07-2010, 08:48 AM
Maybe you just have really really big lungs. Got a chest X-ray handy you can post on line? It might help us clear this up.
Bobby
12-07-2010, 08:57 AM
Larry,
I never attempted to defend anyone at any time. I also said clearly and repeatedly that I don't have experience with adding the stage. I have no idea what my lung volume or Phillips is and never did the math on AL 80's until the discussion turned towards specific numbers. Through the thread people have said that diving from a single to three stages without a bc was not possible. I don't know if I could dive three and I have said that it seems to me more than I could handle. For me calling out someone as being full of BS & untruthfull without having the experience first hand is not going to happen. But that is just me.
Bobby
phillip1
12-07-2010, 11:11 AM
I did all my dives (since the Razor switch) with 3 AL 80, and I always took my 4L MSR at first, but ended up never using it so I just do not take it on those dives as it is not necessary for me.
As I said before with 2 AL 80's it is very balanced out throughout the dive and is how I dive on every dive all the time, with 3 AL 80's I am slightly negative due to the extra pound or so of the third tank, which is really only 1.5 lbs more or less I think.
I really do not care what people think that is how I dive and it works really well for me and Thomas too by the way, Cristian use a 6L MSR with 3 because he dives a 3mm suit and does not get cold, but on dives with two I think he does not even inflate the MSR at all.
Maybe you will come down here one day or we will meet in Mexico and I will do a stage dive with you and hover, perfectly still at any point during the dive, I swear it works, and I don't even have to use the force either.
phillip1
12-07-2010, 11:57 AM
Your discussion on steel tanks is mind-boggling. The material of the tank has nothing to do with its buoyancy shift. NOTHING. It's almost comical, because lots of people are diving steel tanks with no real buoyancy compensator and they truly are staying neutral the entire dive. They are using a drysuit to compensate for buoyancy shift.
Were did I say the material of the tank has anything to do with the buoyancy shift in steel tanks? I was simply saying that since steel tanks have a completely different buoyancy characteristics than AL tanks and since I have no experience with steels I don't know how they would work, but I said I bet they would work, obviously not without a BC device since they are way more negative, duh!!!
And yes I know about using a drysuit as a BC device too, duhh again!!! All my friends in France use they're drysuit as a BC device.
You may think I am a liar but I swear I am not as dumb as you think I am ..lol
phillip1
12-07-2010, 04:03 PM
So I actually sat down for a moment and calculated the buoyancy shift in my tanks, I suck at math so I may be wrong but I don't think so, but then again I suck at math so....
I use Catalina Aluminum 80's which weigh in each at -1.6lbs full and +2.8lbs empty (according to Catalina)
I always end my dives with half or more gas left in my tanks as I never dive to thirds, so half a tank would then weigh about +2.2lbs each and be a +2.2lbs buyancy shift each X3 = +6.6lbs shift, I think. Again I suck at math so I may be wrong, however I am really good at table tennis.
My valves each weigh about a pound or so, so that is -3 (3 tanks) and my canister is a 12w Light Monkey LED which weighs about -2lbs at most + I wear a 3lbs weight on my harness now so it is = -8lbs of constant weight + -4.8 (3 al 80's) at the start of the dive, for a grand total of -12.8. (I am not counting reels and other small negatively buoyant items as that always changes on each dive and really makes little difference anyway)
I dive a 7mm wetsuit with a 3mm hooded vest which are all very positive but I have no idea how much but I suspect around 10lbs more or less.
Now as I have said before I am a bit negative at the very start of the dive with 3 AL 80's, but there really is only a true 6.6 lbs shift more or less, from start to finish, during my dive I perfectly control my buoyancy and can hover in place at any time no problem, with 3 AL 80's each at half tank at the end of my dive at either the safety stop or deco stop I can also stay in place and control my buoyancy perfectly, if I am above 3mtrs I am a bit positive, but nothing that would warrant me wearing any more weight at all.
In an emergency if I were to breath all my tanks down to zero, (which is what some of you assume I do and assign me the maximum buoyancy shift into your calculations of how I cannot be telling the truth about how I dive), I would be dead but still in control of my buoyancy through lung volume alone anyway as the buoyancy shift from full to totally empty would only be +12 (3 AL tanks) offset by -8lbs that I have on me as constant weight, so that would put me at +4lbs of real buoyancy to compensate for so to speak I mean very manageable, and you guys also do not factor in that my lungs would be full of water and that would further help me maintain a neutral position in the water column with empty tanks.
Now with 4 tanks I use a 6L MSR bag with only a small amount of air at the start and with 5 to 6 I will dive my Armadillo, which I find much more manageable with that many tanks on.
My Armadillo has two 2lbs chest weights, a very cool looking Armadillo logo and really tough looking fabric on the wing.
Slüdge
12-07-2010, 07:47 PM
Your math is fine - Catalina's numbers are wrong. A cubic foot of air weighs 0.0807 pounds, so 80 cubic feet weighs 6.456 pounds. Two thirds of that (for a typical cave dive where a third in and a third out are breathed) is 4.304 pounds. Times three tanks is 12.912 pounds buoyancy shift.
Now weight is one thing, buoyancy - another. Come on Slüdge!
phillip1
12-08-2010, 06:57 AM
I think the shift is more around the 6-7 lbs, and I also think Catalina's numbers are correct, but whatever really that is beside the point, I dive this way on every dive and it works for me.
Others who dive the Razor either do it on lung volume alone (2 AL tanks) or use an MSR bag and require a very very minimal amount of lift.
Believe it or not, with Aluminum tanks when you are properly weighted you need a very minimal amount of weight, and although I thought I was properly weighted, before starting my training with Steve, I was, like many others using my wing or harness (Nomad/Armadillo/BM Apeks wing) to compensate for the extra weight, which was not that much I was only about 3-4 lbs overweight, but shedding that and getting everything fine tuned with the Razor has allowed me and many others to dive without the use of a BC device and use lung volume to control my dive.
Without that extra weight all I needed to do was compensate with my lungs at the start of the dive when a bit negative and then I was good to go, I discovered I was only using a very minimal amount of air in my wing or Nomad to compensate for the slightly negative at the start, which I could have done on lung volume no problem, but I did not really know it at the time since I was so used to having a wing on every dive.
It is only after I started diving the Razor that I realized I really did not need the MSR bag or any BC device. On one dive with the Razor like my third I think, I did the entire dive thinking I was adding a bit of air in the MSR at the start when in fact the inflation tube was not even screwed in the bag, so I was blowing a bit of air thinking it was helping me control my buoyancy, the whole dive was great and I was in total control and then at the end I realized the tube was not even connected, and... that I did not even need the MSR, Steve cracked up and told me he dives on lung volume alone all the time and thought I was properly weighted then.
Back in the DR and a few dives later, I tried a stage dive 3 tanks with the MSR but with no air and found out that I could perfectly control my buoyancy on lung volume, yes a bit negative at first but nothing I could not control with lung volume, so since then I have done numerous dives sans MSR or BC and it works really really well for me.
Why is this concept so hard for some people to understand? I am not lying, why would I? I swear I dive this way, and really if I would lie about something on the board I would lie about something way cooler than diving without a BC like finding a really big DR secret cave, not diving on lung volume, that actually sounds really lame.
Caves? what caves? there are no caves here.
DA Aquamaster
12-08-2010, 07:27 AM
Now weight is one thing, buoyancy - another. Come on Slüdge!I'm assuming you are being tongue in cheek supportive of Sludge's math.
The expansion of the tank under pressure is slight and has no significant impact on buoyancy, while the weight of the gas added to the tank when it is filled, does.
For example you might get 15 cc's of temporary expansion on an AL 80 during a hydro test to 5000 psi (a lot more expandsion than you get at 3000 psi) and 1 cc of water has a mass of 1 gram and 1 gram equals about 1/453rd of a pound, so the extra 15cc's of volume would now displace about one half ounce of water, adding an extra 1/2 once of buoyancy to the tank.
Personally, I have a hard time noticing that small a change.
phillip1
12-08-2010, 08:18 AM
So Catalina is dead wrong in the weight full vs empty? I don't think so.
To me it feels about right, at the end of my dives with 100 bar in each tanks they really do not feel very buoyant at all and with valve an reg on if I were to let on go it would definitely sink, I have done that by accident a few times and they definitely do not float and sink to the bottom.
For Phillip, who sux at math. I do too. This is an article written by a university physicist who was also a cave diver. http://www.quarrycommando.com/tankbuoy.html
phillip1
12-08-2010, 08:30 AM
OK so according to that I (Think) Catalina is correct in they're AL80 tank weight of -1.6 full and +2.8 empty, I did say "I think"..
I can definitely say for sure that I know the above numbers feel right when diving, and I think feelings are really important, I mean it's what's on the inside that counts...
Slüdge
12-08-2010, 08:33 AM
So Catalina is dead wrong in the weight full vs empty? I don't think so.
The "0.0807 pounds per cubic foot" I referenced is the number we generally use, but that's based on an ambient temperature of 90°F. Here's a more accurate chart:
http://chestofbooks.com/architecture/Building-Construction-V4/Heat-Contained-In-Air.html#table_7
So at 80°F, the buoyancy shift of three 80s dived a third in and a third out would actually be 13.056 pounds.
SuPrBuGmAn
12-08-2010, 11:19 AM
I hate diving theory...
A hellovalot more can be learned by simply jumping in the friggin water.
Merlin Rhoda
12-08-2010, 02:01 PM
So Catalina is dead wrong in the weight full vs empty? I don't think so.
To me it feels about right, at the end of my dives with 100 bar in each tanks they really do not feel very buoyant at all and with valve an reg on if I were to let on go it would definitely sink, I have done that by accident a few times and they definitely do not float and sink to the bottom.
3000 SERIES 3000 psi (207 bar)
S80 7.25 / 184.2 25.9 / 658 31.3 / 14.2
678 24.5 11.1
-1.6 +2.8 +4.1 S63 7.25 / 184.2 21.7 / 551 27.5 / 12.5
552 19.9 9.0
-2.8 +0.7 +1.8 S53 7.25 / 184.2 19.2 / 488 25.1 / 11.4
464 16.8 7.6
-3.8 -0.8 +0.1 S45 6.89 / 175.0 17.7 / 450 20.3 / 9.2
394 14.2 6.4
-2.8 -0.3 +0.5 S40 5.25 / 133.4 25.0 / 635 16.2 / 7.3
350 12.7 5.8
-1.5 +0.7 +1.4 S30 5.25 / 133.4 19.9 / 505 13.6 / 6.2
263 9.5 4.3
-2.4 -0.7 -0.2 S19 4.38 / 111.3 17.5 / 445 7.8 / 3.5
166 6.0 2.7
-1.5 -0.4 -0.2 S13 4.38 / 111.3 12.8 / 325 5.7 / 2.6
114 4.1 1.9
-1.7 -1.0 -0.8 S6 3.21 / 81.5 10.8 / 274 2.6 / 1.2
53 1.9 0.9
-1.5 -1.2 -1.2 S4 3.21 / 81.5 7.8 / 198 1.9 / 0.9
35 1.3 0.6
-1.6 -1.4 -1.4
So a Catalina S80 goes from -1.6 when full to +4.1 when empty, a buoyancy shift of 5.7 lbs.
The math is 4.1 - (negative) 1.6, which is to say 4.1 + 1.6 since a double negative becomes a positive ...
Edit: the table didn't display properly, you can see the original on Catalinas web site at http://www.catalinacylinders.com/scuba.html
phillip1
12-08-2010, 02:23 PM
When I am diving dead I use no air in my tanks in which case some of you would be correct and it would be an automatic 17.1lbs buoyancy shift, however nowadays I am not diving dead anymore and actually use air in my tanks which I meticulously fill before every dive, believe it or not I do not breath my tanks down to zero when I dive without a BC device, (I know! I know! that sounds really hard to believe, I swear it's true!) and end all my dives with 100bar in each tank, so the buoyancy shift is really only 8.55lbs for 3 AL80's, not diving dead.
My bad, I was off by 1.3lbs per tank in my previous calculations, I read the chart wrong and I suck at math too.
I'm assuming you are being tongue in cheek supportive of Sludge's math.
The expansion of the tank under pressure is slight and has no significant impact on buoyancy, while the weight of the gas added to the tank when it is filled, does.
For example you might get 15 cc's of temporary expansion on an AL 80 during a hydro test to 5000 psi (a lot more expandsion than you get at 3000 psi) and 1 cc of water has a mass of 1 gram and 1 gram equals about 1/453rd of a pound, so the extra 15cc's of volume would now displace about one half ounce of water, adding an extra 1/2 once of buoyancy to the tank.
Personally, I have a hard time noticing that small a change.
No, I was rather suggesting that the weight of the gas itself does not directly relate to the buoyancy of the cylinder.
As per the Archimedes' principle the buoyant force does not depend on the weight or shape of the submerged object, only on the weight of the displaced fluid.
I have no reason to doubt Catalina's own chart but for the ones that do - please experiment! Get a tank, a few weights, an angler's scale and play in the pool :0)
FFDiver221
12-08-2010, 03:47 PM
I hate diving theory...
A hellovalot more can be learned by simply jumping in the friggin water.
I dont like theories neither, I like straight facts...Theory just means it might be right, might not......not might mean dead and that is no theory!!!!
DA Aquamaster
12-08-2010, 04:19 PM
No, I was rather suggesting that the weight of the gas itself does not directly relate to the buoyancy of the cylinder.
As per the Archimedes' principle the buoyant force does not depend on the weight or shape of the submerged object, only on the weight of the displaced fluid.
I have no reason to doubt Catalina's own chart but for the ones that do - please experiment! Get a tank, a few weights, an angler's scale and play in the pool :0)That's my point as well. The tank volume is not constant, as it does expand slightly when filled, but even assuming some fairly generous expansion the amount of water displaced by the tank increases by only about 15 cc's, a volume of water weighing about 15 grams, 1/2 once, or .031 pounds.
So we know(within the limits of ball park tank expansion numbers):
1. A full tank displaces no more than 1/2 ounce more water than an empty one - meaning the full tank would have 1/2 oz more bouyancy if the gas in it weighed nothing at all. 1/2 oz is about .031 pounds.
2. However we also know that the gas in the tank does weigh something. in the case of air it weighs .0807 pounds per cubic ft. And with 77 cu ft in an AL 80, the total weight of the air is 6.21 pounds making the tank 6.21 pounds heavier than it was before it was filled.
3. If we then consider the .031 pounds additional displacement of the full tank and subtract that from the added weight of the gas then we know the tank is now approx 6.09 pounds heavier than it was before. Since we have corrected for the change in displacement of the full versus empty tank, then it is in fact going to "weigh" 6.09 pounds more than it did before when it is placed in the water.
4. If your fish scale does not show that, either your fish scale or your measurment techniques are flawed.
Now, the numbers are approximate as tank expansion will vary a bit and the internal volume of the tank will also vary slightly so in any given AL 80 you may have slight variations in weight, displacement and total volume of gas at the service pressure, but 6 pounds of swing weight in an AL 80 is a pretty solid number for the average AL 80.
---
You are partially correct quoting Archimedes. Archimedes was directly talking about mass being a separate issue from the shape of that mass in terms of displacement. But indirectly he was also talking about why boats float.
While a lump of metal of a given mass will have the same negative buoyancy regardless of how the lump is shaped, the same is not true when that lump is formed into a vessel with an internal volume. Different shapes will contain different internal volumes and that will directly impact the displacement of that object.
For example, metal boat hulls using the same amount of metal will displace differing amounts of water depending on the overall shape of the hull because the hull shape, freeboard, etc, all have a direct impact on how much water the hull can displace before water runs in, fills it with water and causes it to sink.
The same is true for a scuba tank:
1. The old Faber 3AA 3180 psi (3498 with a +fill) weighed 38.7 pounds but was notoriously 'heavy' in terms of bouynacy with -14.76 pounds of buoyancy when filled with 98 cu ft of gas.
2. In contrast the OMS 98 had different dimensions and a 2400 psi service pressure (allowing thinner walls with the same 3AA engineering standard) and weighed a similar 38 pounds - but it displaced more water for less material weight and consequently was only -7.73 pounds buoyant when filled with 98 cu ft of gas.
3. The Worthington X7-100 is designed to a different standard with a different steel alloy and thinner walls compared to 3AA tank of similar service pressure and as a result it weighs only 33 pounds and is only -2.5 pounds bouyant when filled with roughly the same volume of gas.
In effect, tank design is a complex balance of tank shape, material selection and wall thickness - factors that all must be considered to create a tank of adequate strength with minium weight and a very specific buoyancy swing. In general the challenge to a structural engineer is not to make things stronger, but rather to get the neccesary strength with less weight. Tank design adds another element in terms of also having to produce a tank that is not overly negative when full.
-----
The theory free version:
If you jump in the water with a full X7-100 you will sink
If you jump in the water with a full OMS 98 you will sink more
If you jump in the water with a 3180 psi Faber 100 you will sink a lot more.
phillip1
12-08-2010, 05:02 PM
I would like to add to that if I may,
If you jump in the water with a full Catalina aluminum 80 you will not really sink that much at all.
Bobby
12-08-2010, 07:09 PM
I must say I have had about enough of this thread even though it has been entertaining. If I go to the ocean over the holiday break I will be monkey diving, most likely, with an AL 80. I will do my best to not die or become a rocket breaking the surface at warp speed. Do all the math anyone would like, I am just going to go diving.
Bobby
Slüdge
12-08-2010, 08:12 PM
Point of information, I believe Catalina considers a cylinder "empty" when it has 500psi.
phillip1
12-09-2010, 06:28 AM
I must say I have had about enough of this thread even though it has been entertaining. If I go to the ocean over the holiday break I will be monkey diving, most likely, with an AL 80. I will do my best to not die or become a rocket breaking the surface at warp speed. Do all the math anyone would like, I am just going to go diving.
Bobby
Yeah really me too
caver
12-09-2010, 03:40 PM
Diving without the use of a BC...
An example : http://monkey-diving.com/index.php?option=com_content&task=blogcategory&id=17&Itemid=33
What are your opinions on this form of diving, and why? :smt102
Is this what you are talking about?
Slüdge
12-09-2010, 06:13 PM
Is this what you are talking about?
No. The sign specifically says, "No diving."
phillip1
12-10-2010, 11:39 AM
not to start **** again but I think Steve is diving sans BC device here.
http://www.youtube.com/watch?v=TSV91lQPgnk&feature=sub
As I said before he dives like that most of the time with 3 AL 80's too, so there..lol
Kidding aside Steve is a kick **** instructor and I learned basically how I dive today from him, and it completely changed my entire view of diving and me as a diver for the way better.
I am not sure if he came up with this way to dive but it appears he is the only one teaching this specific minimalist SM style and the many techniques and procedures that go with it.
...I am not sure if he came up with this way to dive but it appears he is the only one teaching this specific minimalist SM style and the many techniques and procedures that go with it.
The CDG (also from England) have been diving that way for years.
OneBrightGator
12-10-2010, 01:50 PM
not to start **** again but I think Steve is diving sans BC device here.
http://www.youtube.com/watch?v=TSV91lQPgnk&feature=sub
As I said before he dives like that most of the time with 3 AL 80's too, so there..lol
Kidding aside Steve is a kick **** instructor and I learned basically how I dive today from him, and it completely changed my entire view of diving and me as a diver for the way better.
I am not sure if he came up with this way to dive but it appears he is the only one teaching this specific minimalist SM style and the many techniques and procedures that go with it.
That's a pretty cool video, but there are plenty of shots where you can clearly see the MSR bag.
His website talks about how he uses an MSR bag, even for no-mount dives.
ffdiver5597
12-10-2010, 04:51 PM
Any time I watch one of his videos, I want to go straight out and dive sidemount.
timle
12-10-2010, 04:54 PM
Clearly not using an MSR bag. LOL
Its clearly visible in many of these shots covering what looks like many different dives - from the caves, to the wreck, to the playing around in open water. The inflation tube runs from the small of his back, in front of his right shoulder, around his neck, and then rests on his left side.
phillip1
12-10-2010, 04:54 PM
I guarantee you Steve dives a lot too without the MSR bag.
Agreed the CDG dive like that but it is more sump diving, it appears and I may be totally wrong that Steve is the only one in recent years to dive this way (Razor style harness, no BC etc..) in cave diving.
I have seen many people dive SM, but none really configured like Steve other than people who trained or were inspired by the whole Razor thing.
Then again I don't get out much out, other than Mexico and the DR I have not dove any caves in other countries, but judging form youtube videos and such it seems like all the ones who dive a similar type harness were kind of inspired by Steve's Razor and diving style.
I am only talking about cave divers not sump divers, I know sump divers have been up to that for years, I mean adapting that type of thing for "mainstream" cave diving.
CaveBuddy95
12-10-2010, 09:20 PM
Not sure there is a sump diving certifying agency anywhere..!! :) This is more speleology and its tools to get where needed be.
Sure Steve got inspired by it, maybe. After all, he is a Brit and most longest sumps are in the UK. But thats another topic.
On this video Wreck diving in SM (http://www.youtube.com/watch?v=yDp58Wrz4Uk) you see the first prototype/use of hydration bag. It was a Camelbag. And judgjing by the air volume, its really minimal. It is in salt water.
No worries, Steve is out there preaching the word and soon enough it will reach the new continent! ;)
Not sure there is a sump diving certifying agency anywhere..!! :)
The CDG does teach sidemount (mostly for sumps, but they do have some springs too), and now some of their instructors are certifying through a British agency, BSAC. The British word for certify is qualify, and both the CDG and the BSAC do "qualify" sump and cave divers.
FWIW, I know a lot of US, as well as French cave divers that use a minimalist rig like the Razor. Some are even smaller and simpler.
I will agree that Steve was the first to bring minimalist sidemount to Mexico.
phillip1
12-11-2010, 06:40 AM
I think that as far as using the sump diving set up, so to speak, for cave diving Steve is the only one who teaches that as far as I know.
I know there are divers who dive sumps and have been diving a Dragon (sump) type harness since day one, but I think they are few and far between in using that same harness as a full on cave diving configuration.
Martin Farr came to dive here a few years ago to cave dive and he was diving BM and a regular SM setup, I think it was a Dragon with a jacket type BC like Forrest used when he came here.
Divers like that have been doing that under the radar since day one, but I think Steve who was not really happy with either of the available cave diving SM harnesses and looked elsewhere for a better way to do it and saw the potential for cave diving of sump type harnesses.
It may be nothing new to people like Forrest, the CDG and sump divers, but to everyone else in cave diving it's a true revolution and Steve is the only cave diver not sump diver to have realized the potential of such a configuration.
Granted I dont get out much aside from Mexico and the DR but I have yet to see a photo or a video with a cave diver, not a sump diver, using a Dragon/sump type harness for cave diving, prior to Steve releasing the Razor.
For me, an average cave diver, it totally blew my mind and I would have never thought a weird setup like that would work so well.
CaveBuddy95
12-11-2010, 10:09 AM
Right Forest, I forgot about the CDG! My bad. Me and my recreational cave diving views... :)
Probably true, Steve brought that minimalist approach in Mexico. And on top of that, after ripping a few Armadillo or other Nomad going through extremely small passages, the option for simple webbing harness became an obligation, a necessity. In a blog somewhere, there are some pics of an abused rig from Steve, the OPV on his 'off the shelves' rig is near dead. Simply because of where its located, the high profile and the gnarly stupidly small caves he is going through.
Now that, we, common mortals, have issues in understanding how to 'make' it work in our everyday dives is no surprise. Because simply, it was not designed for open water diving. But guess what? It works. It is so balanced, its unbelievable. No matter if you are in fresh or salt water. I am not saying that after an open water course you should go and dive the Razor. It is made for divers who accept and understand the consequences of its use.
Advanced sidemount caves cannot really be dived in drysuit. For some obvious wear and tear issues as well as restricted movements. This is probably why, even in the CDG, drysuit come in the last resort.
OneBrightGator
12-11-2010, 10:36 AM
I guarantee you Steve dives a lot too without the MSR bag.
When it comes to how Steve dives, I'll believe his own words on his website and multiple videos he posted before I'll believe what you have to say.
phillip1
12-11-2010, 11:08 AM
oh yeah I forgot, I'm a liar, ooops my bad
Advanced sidemount caves cannot really be dived in drysuit. For some obvious wear and tear issues as well as restricted movements. This is probably why, even in the CDG, drysuit come in the last resort.
Actually most of their diving is in drysuits. It is way too cold up there to dive wet. I do suspect they ruin a lot of drysuits in their sumpdiving career. I have destroyed six drysuits so far, and I don't dive in water that cold.
CaveBuddy95
12-11-2010, 12:15 PM
I don't think its 100% correct. I found this info here (http://www.cavedivinggroup.org.uk/Essays/Scoff.html)
For far away sumps, they bring along a drysuit, in a drybag to be donned later. Thats how I understand it.
Maybe I'm wrong :)
phillip1
12-11-2010, 01:51 PM
Them sump divers seem like a much more hardcore and dedicated group than us lazy cave divers (at least me as a lazy cave diver)
I mean yeah I walk around the jungle a lot looking for caves (which is a lot more than many cave divers do anyway) but that's child's play compared to negotiating a dry cave for hours, ferrying gear, dive a sump, emerge on the other side and do it all over again.
Much respect!
I don't think its 100% correct. I found this info here (http://www.cavedivinggroup.org.uk/Essays/Scoff.html)
For far away sumps, they bring along a drysuit, in a drybag to be donned later. Thats how I understand it.
Maybe I'm wrong :)
I said "most", It is hard to do the "dry" cave in a drysuit, you get too hot.
mwenner
02-27-2011, 07:11 AM
Them sump divers seem like a much more hardcore and dedicated group than us lazy cave divers (at least me as a lazy cave diver)
I mean yeah I walk around the jungle a lot looking for caves (which is a lot more than many cave divers do anyway) but that's child's play compared to negotiating a dry cave for hours, ferrying gear, dive a sump, emerge on the other side and do it all over again.
Much respect!
Oh ya, sure Phillip! Cross the sugar cane fields until your truck bumpers fall off, get the gear on donkeys, and try to keep your gear away from the barbed wire fences, rig and drop, and then sump dive! :) Who would want to do that?
Just hold up a bottle of Don Julio...... I'm there.
Puttzer
02-28-2011, 07:14 AM
Diving without the use of a BC...
An example : http://monkey-diving.com/index.php?option=com_content&task=blogcategory&id=17&Itemid=33
What are your opinions on this form of diving, and why? :smt102
Kind of reminds me of Mike Nelson.
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