Long/thinner tanks - ideal for cave diving??

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03-02-2006 02:38 PM
andrebasso

Long/thinner tanks - ideal for cave diving??

Whazz up everyone? Hope the caves down there are treating you all well, I've been having withdrawals since I came back to NYC. Suddenly, Dutch Springs doesn't seem like much of a spring anymore. :? :x :evil:

Got a quick question. The other day I was swimming through the Gallery at Devil's Eye and I thought MAN, there has to be a better way to stream line my gear to cut down on the drag! Removing excess ballast will cut down on the drag imposed by an overly inlflated BC, but another thing came to mind - long tanks... Does anyone know if a manufacturer makes a 95-105 cft cylinder that is both very long and considerably thinner in diameter. I think this would be the ultimate for cave diving, alot less drag on your back.
03-02-2006 02:47 PM
Caver95

not that I know of, but you can get alot of gas into Lp 85s they are much nicer that those big tanks,
03-02-2006 03:04 PM
Jason B.

Re: Long/thinner tanks - ideal for cave diving??

Quote:

Originally Posted by andrebasso

The other day I was swimming through the Gallery at Devil's Eye and I thought MAN, there has to be a better way to stream line my gear to cut down on the drag!

Swimming in the Gallery is tough with all that flow. Were you swimming along the gold line or were you up high and out of the main flow?
03-02-2006 03:22 PM
Tegg

Re: Long/thinner tanks - ideal for cave diving??

Quote:

Originally Posted by andrebasso

The other day I was swimming through the Gallery at Devil's Eye

Swimming? That's your problem... :-D

I don't own a scooter (yet) and I don't swim through the gallery...
03-02-2006 03:24 PM
andrebasso

Hey jason,

No, I was all the way up at the top... Those 104's on my back are like a sail.

I guess this is why people buy scooters...
03-02-2006 03:27 PM
andrebasso

Re: Long/thinner tanks - ideal for cave diving??

Quote:

Originally Posted by Tegg

Quote:

Originally Posted by andrebasso

The other day I was swimming through the Gallery at Devil's Eye

Swimming? That's your problem... :-D

I don't own a scooter (yet) and I don't swim through the gallery...

You mean, you need to pull and glide through the gallery? :D
C'mon the flows not that strong.
03-02-2006 04:13 PM
CaptainSpeleo

andrebasso:

Thin tanks are about 7-1/4" in diameter and fat tanks are about 8" in diameter, so that's going to have no real effect on drag. What's going to have a noticable effect on drag is body size, swimming technique, and gear configuration.

Frank
03-02-2006 04:55 PM
JDR

The trick isn't in the size of the tanks, it's in the frequency of use. IF you quit your job, move to Florida, and dive every day, the tanks will feel like an AL 80 when OW diving in Bonaire. The cost of living in north Florida is ridiculously inexpensive compared with NYC. So, the solution is: Quit your job and be a dive bum. You will never drive a Bentley, but who needs a Bentley!!

Cheers and safe diving,
Dive Bum
03-02-2006 05:39 PM
Rich

Quote:

Originally Posted by JDR

So, the solution is: Quit your job and be a dive bum.

LOL, I can relate to that.... :-D

Safe diving,

Rich
03-02-2006 05:57 PM
Arnold Mesiser

Quote:

Originally Posted by CaptainSpeleo

andrebasso:

Thin tanks are about 7-1/4" in diameter and fat tanks are about 8" in diameter, so that's going to have no real effect on drag. What's going to have a noticable effect on drag is body size, swimming technique, and gear configuration.

Frank

I perfected the human manatee shape hoping for an equal ability to effortlessly glide through the water.Man did that not work :?
03-02-2006 06:58 PM
HomoErectus

Quote:

Originally Posted by JDR

The trick isn't in the size of the tanks, it's in the frequency of use. IF you quit your job, move to Florida, and dive every day, the tanks will feel like an AL 80 when OW diving in Bonaire. The cost of living in north Florida is ridiculously inexpensive compared with NYC. So, the solution is: Quit your job and be a dive bum. You will never drive a Bentley, but who needs a Bentley!!

Cheers and safe diving,
Dive Bum

Why dont you let the man have a real life?
Adnrea, Rich and JDR are examples to avoid. Especially, JDR has been on vacation for the last 5 years. His only job is diving and exploring caves even if they are not virgin. hahahahahahahaha
03-02-2006 08:55 PM
andrebasso

Quote:

Originally Posted by Rich

Quote:

Originally Posted by JDR

So, the solution is: Quit your job and be a dive bum.

LOL, I can relate to that.... :-D

Safe diving,

Rich

Don't tempt me guys, I'm actively considering it...
03-02-2006 10:00 PM
JDR

Temptation is the first step, followed by large quantities of diving. All of the conspicuous consumption items can be liquidated :wink:

Life is good when diving is a PRIORITY!!

Rich, how's diving now that you are a papa?
03-03-2006 12:18 AM
WaterDawg

Quote:

Originally Posted by eramosakarst

I perfected the human manatee shape hoping for an equal ability to effortlessly glide through the water.Man did that not work :?

LOL!!!!! Time for plan "B"!
03-03-2006 04:04 PM
Moonfuzzy

Back to the subject at hand.... ; )

I use Genesis 100's and Gary uses Genesis 120's. They have a noticably smaller diameter than LP 95's.. but the 120's at 3500 hold about the same.

Just remember that the 120's are longer - If I borrow his tanks they are banging the back of my legs on the dive. I am 5'5" - Gary is 5'10" or so.
03-03-2006 04:46 PM
muzz

learn how to use the cave. What I mean is, find the spots with less flow.
03-03-2006 07:45 PM
Rich

Quote:

Originally Posted by JDR

Rich, how's diving now that you are a papa?

As good as ever, we're going to try the car seat in the ambulance tomorrow... :-D

Safe diving,

Rich
03-03-2006 07:53 PM
andrebasso

Quote:

Originally Posted by Moonfuzzy

Back to the subject at hand.... ; )

I use Genesis 100's and Gary uses Genesis 120's. They have a noticably smaller diameter than LP 95's.. but the 120's at 3500 hold about the same.

Just remember that the 120's are longer - If I borrow his tanks they are banging the back of my legs on the dive. I am 5'5" - Gary is 5'10" or so.

Hmm, sounds just like what I'm looking for, but are these AL or steel tanks??
03-03-2006 08:01 PM
curtschu

Same old problem

Genisis and even the new HP tanks have the same old problem. If you get a good fill great. but if the pimple face kid does not understand and gives you a 3500 fill that cools to 3200 you have less gas. If you use LP tanks you get a good fill (cavefill) great you got the gas you want. but if you only get a 2649 fill at least you know you have rate volume.

Anyway just my .02

Curt
03-03-2006 08:08 PM
Limestone Cowboy

Technique and trim are about 100x more important. Ditch the danglies, streamline, get horizontal, find the shadows in the flow, Pull and Pull when appropriate, and be as comfortable and chilled out as possible. You'll get the results that way much faster and cheaper.

Good Luck, Drew
03-03-2006 10:48 PM
Moonfuzzy

Quote:

Originally Posted by andrebasso

Hmm, sounds just like what I'm looking for, but are these AL or steel tanks??

They are steel tanks.

I can notice the differance when I swim my tanks vs 95's, and mine are lighter - big bonus for me. (the 100's are more comparable to LP 85's in volume) When I dive 104's I feel like I am driving a semi!

Where you really notice a differance is in tight cave.. I think that the diameter is like 1" or so smaller, which doesn't matter in Ginnie mainline but that makes a big differance in the Wormhole ; ) You have more clearance, so you can dive cleaner and make no contact - what we should all be striving for ; )

I do agree with the comment about improving technique. If you already own tanks I don't know if it is really worth it to buy new ones for the streamline affect... technique and trimming gear out will get you far with much less coin.

I have NEVER had a problem getting a fill for my tanks to rated pressure in cave country. Outside of the area I have been impressed.. maybe I am using tech-friendly shops but I have not really had problems getting fills to 3500 in the Keys or West Palm.
03-04-2006 05:54 AM

Pressed Steel HP-100s are identical to their LP-80s except for the size of the necks. They are a tad smaller and a tad heavier than Faber LP-85s.

The diameter of the HP-100s and HP-120s is 7.25 inches - the same as aluminum 80s.
03-05-2006 06:28 AM
BillGraham

Quote:

Originally Posted by Limestone Cowboy

Technique and trim are about 100x more important. Ditch the danglies, streamline, get horizontal, find the shadows in the flow, Pull and Pull when appropriate, and be as comfortable and chilled out as possible. You'll get the results that way much faster and cheaper.

Good Luck, Drew

Yup, that's the ticket. I got shot out of there like a cannonball until my friend showed me where to go to stay out of the flow. As you dive more, ducking into the "shadowed" areas becomes second nature.

I know that you've got a lot to figure out right now but you might look at sidemount down the road if you're really interested in streamlining. I personally don't think tank size has much to do with anything once you're in the water. The amount of gas in your wings is probably more significant so getting your weighting dialed in is the best first step.
03-05-2006 06:46 AM
Cindy

Boy, I wish Bill Main would post! He would have something to say about sidemount "improving" streamlining. Most sidemount divers are far from streamlined. I love sidemount diving because it's easy on my back and I can get into tiny caves but backmounting is what I do in large high flow caves and I need to use multipal stages and scooter. It's just easier and I don't have to worry about even more stuff hanging off my chest. Learn technique first. Then go with what gear you used in class until you are comfortable with diving in caves. Learn how to be a great swimmer first and scooter later, you will save your life some day. Then learn how to adjust the gear you have to the cave that you want to explore. You will be a better and more flexible diver. If you learn to adapt, think problems through and remain calm you will last a lot longer at cave diving than thinking up little details about the size of tanks. I know you guys are bored. I'm pretty sick of work and ready to get outdoors and do some diving myself. Have a good one, Cindy Butler :D
03-05-2006 04:55 PM
andrebasso

That kind of makes sense, staying in those low flow area where the eddies are formed by the current. Good advice guys. Guess I have lot's to practice... back to the tanks though, I realized it really isn't so much the tank diameter but the weight of the tanks. If you have tanks that are perfectly weighted for you, then you'll have the minimum amount of air in the BC. Thinking back on my trip to Ginnie - my wings were inflated like a balloon. Those old PST 104's I was renting were made of pure lead. I definitely need lighter tanks. :smt051
03-05-2006 06:57 PM
D1V3R

didnt poseidon come out with a doubles system based on 2 low profile tanks?
I think each tank was only like 60 cu. ft. though, so you would be better off with a single 120 in that case.
that would probbaly be good for sump diving, like as an extension to side mounting because tank size is so limited (unless you're 7 feet tall, lol)
03-05-2006 08:47 PM
Arnold Mesiser

Quote:

Originally Posted by D1V3R

didnt poseidon come out with a doubles system based on 2 low profile tanks?
I think each tank was only like 60 cu. ft. though, so you would be better off with a single 120 in that case.
that would probbaly be good for sump diving, like as an extension to side mounting because tank size is so limited (unless you're 7 feet tall, lol)

Interspiro
03-05-2006 09:05 PM
Limestone Cowboy

Quote:

Originally Posted by andrebasso

Those old PST 104's I was renting were made of pure lead. I definitely need lighter tanks. :smt051

HHmmmmmm....

Figure out how many pounds of air were in those tanks.....then think about trying to swim out of a cave minus ALL of that weight after the excrement hits the rotary cooling device.

Just food for thought.

Drew
03-05-2006 09:15 PM
andrebasso

I actually thought about that, towards the end of my last dive I breathed them down to 500psi to test them - still very negative. Darn, I wish I remember exactly which model they were. I think I remember Bill Rennaker saying they were made in the 90's.
03-06-2006 09:35 AM
Moonfuzzy

Found this in the resources section, lots of info on tank specs:

http://diverlink.com/gear/tankspecifications.htm

At almost the very bottom of the page is a section on tank specs by manufatcturer. There are sized, capacities, and bouyancy info.
03-06-2006 05:45 PM
D1V3R

http://www.poseidon.se/index.asp?LangID=4

here is the poseidon setup i was talking about
i'm sure it could be useful in some tight restrictions, but it wouldnt see much use outside of those unique situations

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