UWS Article - 7 Days in the Dark - GEM

[netmage]

So whats the skinny on the 'GEM Gas Extender'....?

-Tim

[FW]

It is an SCR type rebreather. It uses back/side gas only, no O2. Similar concept to the old Draeger rebreathers, but more efficient. Send a PM to deepairmike for more information.

[SLIM]

The GEM is the only SCR I will ever use. It has so many options and a great design. Deepairmike is the one who desigens and builds it.

It was basicly designed for that system and a few others for the Gas Extension that it provides. So many fetures that can be put into it.

I love mine and use it as much as I can.

No electronics or soliniods to go bad.

SLIM

[rjack]

Designed for which system?

I'd like to hear more, is this an rb80 clone or something unique?

[deepairmike]

it works on the same principals as the RB80 but the discharge happens in the mouth piece not in the counterlungs. I can go as high as 20-1 ratio over O.C.
I like to wear mine on doubles that way I have 2 systems and full O.C. Bail out!!!

[netmage]

pictures - pictures... :)

rig weight?
lbs of scrubber?

[rjack]

Pictures, description!!! Scrubber size+design? frame? tanks? BOV type?

[JahJahwarrior]

and cost...that too!

[awindhorst]

Is there someplace or a website that we can see the GEM. It sounds pretty interesting.

[deepairmike]

The system is compleatly modular you can put as big or as small a scruber as you want. It can be mounted on doubles or single 80. Cost is about $2000 and includes trianing.

[rjack]

Is this a passive design or keyed to breathing?
Assuming the backgas is breathable at depth (i.e. bailout). How do you address the ppO2 drop?
Does it have any o2 sensors at all?
How does the WOB compare with other units?

I'm way over in Seattle, what's the best way to learn more about it?

[deepairmike]

Is this a passive design or keyed to breathing?
Assuming the backgas is breathable at depth (i.e. bailout). How do you address the ppO2 drop?
Does it have any o2 sensors at all?
How does the WOB compare with other units?

I'm way over in Seattle, what's the best way to learn more about it?

it is keyed to breathing a portion of every breath is discharged. you can use o2 monitor but after a few dives you trust it does what its supposed to do. talk to Slim to see about training.

[icestac]

Got a website or anything? Google was useless

[deepairmike]

Welcome to sane and safer re-breather diving! The GEM V6 re-breather is the culmination of years of research, design and test diving with emphasis on simplicity, versatility and safety. In fact, there’s been a lot of effort and thought put into making this system simple. This manual will first show you how the GEM is different than all other re-breathers, then thoroughly explain operating principals and parameters while moving you toward an understanding of how to dive with the re-breather. This manual is only a guide to learning. You must take the manufacturer's certification course in order to use the GEM safely.
The GEM - A Gas Extender
Think of the GEM as an extension device of your available gas supply. Imagine a single 80 cubic foot tank with the help of the GEM can give you 4 to 8 hours of bottom time!

Semi closed circuit re-breathers add breathing mixture continuously and waste gas in the process. The valves can become inaccurate or dirty giving you too little or too much gas. Fully closed re-breathers try to control use of gas by separating components of your breathing mixture and mixing them on the fly with the sophisticated use of electronics - sometimes with disastrous results. The GEM is a completely different approach using the exhale exhaust / demand addition concept.
As you exhale, the mouthpiece automatically exhausts up to 25% of your exhalation. The rest of the gas continues through the counter lung to the scrubber where most CO2 is removed. As the gas travels to the inhalation lung the system equalizes pressure by activating an automatic demand valve that restores the volume of the lung with fresh gas. The GEM operates on sound physical responses both in your body and in the environment. Therefore, the GEM does not waste gas and valves do not become clogged like a continuous adding re-breather. Unlike closed circuit re-breathers it does not rely on finicky electronics which can be plagued by bad sensors, dead batteries or solenoid valves that can malfunction either slamming shut or open permanently, usually at the worst time. Simplicity IS safety!
The GEM has several other advantages that should enable you to experience instant and very apparent awareness of any system failure. If the demand valve fails to work, the system becomes slowly more difficult to breathe and you have several breath cycles to bail out to the integrated open circuit system or add gas to the loop manually. Both with exactly the same depth appropriate gas mix. If the demand valve free flows you can recognize it and take action. You will be immediately aware if the system is not exhausting gas because you monitor it yourself - by watching for a small stream of bubbles. There is no chance of oxygen toxicity if you dive within the parameters of the system, your gas mixes and follow the rules. The GEM has been designed so that scrubber "caustic cocktail" is unlikely . The system is completely redundant. At any time you have at least two fully independent breathing systems.
In addition to these features you have the ability to change gas mixtures as many times as you want any time during the dive. The GEM allows you to decompress on ANY oxygen mix up to and including 100%. Rig your system any way you want - it can be rigged back mount, single or double tank, side mount, you can carry stage bottles and if you really have a need the GEM can be set up for no mount! It’s all about simplicity, safety and versatility.

An Introduction to the System
The GEM is an integrated system composed of a few simple parts: the exhausting mouthpiece, large diameter breathing hoses, two liter exhaust and inhale counter lungs, a large capacity scrubber vessel, and the automatic demand valve. All parts of the re-breather are easy to disassemble for service or cleaning. Let’s take a look at the individual components.

Unlike other re-breather systems and because of the proprietary design of the GEM mouthpiece, it can be used in any swimming position. Unique magnetic valves control the exhaust rate of the mouthpiece from 10 to 25% of every exhalation. Each mouthpiece is set for a certain exhaust ratio (from 3:1 to 6:1) at the factory. For training, open water and non-technical diving mouthpieces are supplied that have a ratio of 3:1, exhausting about 25% of each exhalation. This insures a good gas extension effect while adding more safety to the system. Technical divers who have taken the technical GEM Re-breather course will be able to purchase mouthpieces that have a ratio of up to 6:1 with exhaust rates as low as 10%, drastically increasing the gas extension effect. The mouthpiece also features an integrated on-off valve so you can completely close the unit when it is not in use. *** address where to stow the re-breather hoses when not in use

The breathing hoses are flexible high flow corrugated tubes with integrated weights to suit the individual diver. The hoses help ensure that breathing effort is kept to a minimum.

The two counter lungs are mounted over each shoulder so breathing is not affected by pressure differentials and is much more natural. They are constructed of heavy-duty ballistic Cordura nylon and are easily mounted to any harness system.

The scrubber vessel houses five pounds of the scrubber material of your choice and is an efficient center tube design to reduce "channeling". The scrubber housing is made of heavy duty clear cast acrylic making it easy to view water intrusion or scrubber color change.
The automatic demand valve is machined into plumbing at the top of the exhalation counter lung and features a quick connect inlet from the available gas supply. The quick connection allows you to plug in any gas mixture.

The basic GEM comes complete with all the items listed above so that you can build the system that is right for you with your selection of BCD/Wings, harness, first stage regulators (at least two are needed) and weight systems. You can add other options such as an O2 monitor, manual addition valve, integrated weight system or water dump valve at any time.


A Few Hard and Fast Rules (that should always be followed)
1. Shallow dives (2 ata or less) must be done with at least NOAA Nitrox Mix #1 or 32% enriched air. NO AIR DIVING ABOVE 33’!
2. You must be trained in Enriched Air to use the GEM. For
the technical program you must be trained in Advanced Nitrox.
3. All ascents must be made slowly.
4. Flush the loop every 15 feet of ascent.
5. Dives WILL NOT exceed the Maximum Operating Depth (MOD) of the gas supply used.
6. The re-breather loop must NOT be used on the surface.
7. Always do at least a 5-minute safety stop at 15 feet and start the safety stop by flushing the loop.
8. Keep a log of time used on the scrubber material and never exceed its exhaustion time.
9. Notice problems. If you detect any problem before, during or after diving the GEM - take care of the problem immediately!
If you always follow these simple rules, chances are you will live long enough to enjoy the GEM Re-breather for thousands of hours. Lets go through each rule and see why they’re important.

Rule 1 - Shallow dives (2 ATA or less) must be done with at least NOAA Nitrox Mix 1 or 32% enriched air. NO AIR DIVING ABOVE 33’!
We might add no hypoxic mixes above 2 ATA either. As you use the re-breather on an air above 2 ATA, the system is supplied with only 21% oxygen. As you breathe you exhaust up to 25% of that volume air and your body uses about 16% of the available Oxygen in the remaining volume. The GEM through its automatic demand valve makes up for the loss of volume, but only replaces a tiny bit of the 16% deficit of oxygen in the loop because it is supplied with an air or a 21% mix. After a few breaths the gas in the loop becomes too hypoxic to sustain brain function, leading to unconsciousness.
Below 2 ATA (33 feet seawater) air can be used because the increased ppO2 in the air mix (due to pressure) does not let the loop fall to hypoxic levels. The same is true when using NOAA Nitrox #1 (32% oxygen) above 2 ATA. The increased oxygen in the mix does not let the loop fall below 21% O2 into the hypoxic range.

Rule 2 - You must be trained in Enriched Air to use the GEM. For
the technical program you must be trained in Advanced Nitrox.
It’s simple, for even open water recreational diving with the GEM, you must have a clear understanding of Nitrox theory and practice. You must be able to calculate your Maximum Operating Depth (MOD), Equivalent Air Depth, and understand the effects of Oxygen Toxicity and how different gas mixes will effect decompression.

Rule 3 - All ascents must be made slowly.
Remember "shallow water black out" from your open water certification course? Re-breathers can cause the same problem. If you are at depth and make a quick ascent the partial pressure of the gas in the loop can drop dangerously low and becoming hypoxic before the automatic demand valve can catch up. Here’s how it works: as you start your fast ascent on let’s say a 32% mix, depending on depth the ppO2 in the loop will be hovering around 22%. Remember, you are exhausting up to 25% of every breath and only adding that much back to the loop each breath. In addition, the volume of air is expanding in the loop because you are ascending to lower ambient pressure. Because of the decreasing water pressure the partial pressure of the gas in your loop decreases. The remedy for this situation is very simple, slow your ascent to no more than 30 feet per minute and/or flush the loop every 15 feet or every other breath. Ah....that leads us to our next rule...

Rule 4 - Flush the loop every 15 feet of ascent.
That’s about every other breath if you are making the ascent slow enough. We suggest that you not only go slow on every ascent, but also flush the loop. How is this done? Simply exhale every other breath through your nose. This will expel the entire exhalation from the system and require the automatic demand valve to replace the whole breath (instead of just 25%) with fresh gas in the loop. This INCREASES the ppO2 of the loop and you have plenty of oxygen for your brain. While we are talking about it, think of your re-breather as holding THREE breaths at any one time. This system is not a one for one exchange cycle of inhalation and exhalation. Your exhaled gas "lingers" in the system until it is processed. In effect you are re-breathing several different breaths.

Rule 5 - Dives WILL NOT exceed the Maximum Operating Depth (MOD) of the gas supply used.
This is the rule that makes the GEM so safe and versatile all at the same time. If you never exceed the MOD you will NEVER have to worry about oxygen toxicity. Because you can easily carry different mixes, this is not a limiting factor for depth or decompression. Here is an example: If you are a technical diver and are doing a deep dive that requires a hypoxic bottom gas you conduct the dive much as if you were using open circuit SCUBA You start the dive on a travel gas (let’s say 32% Nitrox) in a stage bottle that is quick connected to the automatic demand valve of the re-breather. You use this mix ONLY to it’s Maximum Operating Depth. The MOD of 32% at 1.48 ppO2 is 120 feet. Because you are conservative, at 100’ you disconnect the 32% Nitrox and connect your back mounted bottom mix of 16/50 and continue your dive to it’s MOD of 268 feet for a very, very long time thanks to GEM‘s gas extension principal! On ascent (you go slowly of course and flush the loop regularly) you switch back to the Nitrox 32% stage bottle at 100 feet and decompress to 20 feet where you have dropped a bottle of 100% oxygen. At that point, you connect it to the re-breather and finish the decompression. You ONLY connect to the 100% bottle above it’s MOD of 20 feet.
Maximum dive time is increased due to the gas extension effect at any depth and the ability to decompress on different mixes. There are many advantages but remember this DOES NOT reduce your decompression obligation!

Rule 6 - The re-breather loop must NOT be used on the surface.
If you are gearing up, or waiting for others to get ready for the dive you must resist the temptation to breathe on the loop. Breathing above 1ata on air or at atmospheric pressure on any gas mix can make the loop turn hypoxic as we explained in rules 1, 3 and 4. After extended surface breathing you could find yourself unconscious under 5 feet of water after starting the dive!

Rule 7 - Always do at least a 5-minute safety stop at 15 feet and start the safety stop by flushing the loop.
Flushing the loop before starting the safety stop assures that the O2 partial pressure in the loop is as high as it can be. This helps off gas nitrogen (or another inert dilution) and helps insure that your tissues and brain are oxygenated. The 5 minute safety stop gives your body almost two blood circulation cycles to clear any excess inert gasses. On to our final but most important rule.

Rule 8 - Keep a log of time used on the scrubber material and never exceed its exhaustion time.
If you don’t know how many hours are on the scrubber material it is far better to replace it with new. Keep a log of hours used, keep it up to date and keep it written on the scrubber container. Failure to replace exhausted scrubber material will prevent the re-breather from functioning as intended and keep it from removing CO2 from the breathing loop.

Rule 9 - Notice problems. If you detect any problem before, during or after diving the GEM - take care of the problem IMMEDIATELY!
The GEM is one of the safest re-breathers, but it is NOT open circuit SCUBA. You must be sensitive to the system and your body. You must understand how the GEM works and how it interfaces and reacts with the environment and your body. Because of its clever and simple design, you will FEEL problems rather than read about them on a computer screen. You must learn to recognize any malfunction and take action to correct the situation. Training is important and so are conditioning experience dives at moderate depths in open water so that you know how to react to problems when the going gets rough, deep and dark.

Fault Detection
The GEM reacts to any fault situation by changing its response to the diver. Let’s take a very simple fault situation to illustrate this point - a mouthpiece that is not exhausting gas. First of all, like open circuit SCUBA you will get used to seeing a stream of bubbles coming from the mouthpiece. Using open circuit SCUBA the stream is very large, but it’s only a small trickle with the GEM. You will most probably notice if you are not producing bubbles, but let’s say you are not paying attention. On a normal dive you will be conditioned to hear and feel the demand addition valve adding gas on a regular basis. In this fault situation, the GEM changes it’s normal response by not adding gas to the breathing loop. The fault situation should be immediately obvious and you take action to correct the problem. This is why a series of shallow "experience" dives are so critical. Experiencing how the GEM reacts when functioning correctly on a normal dive will enable you to better diagnose when there is a problem. This philosophy of fault detection was not a mistake, it was carefully built into the re-breather to give you a fail-safe, simple and clear method to detect and diagnose problems. Really you should consider you and the GEM one unit - the Diver/GEM unit. By the way, the proper response to the fault above is to exhale through your nose or bail out to the open circuit system and abort the dive.

Now, let’s look at some problems, how the GEM reacts and how you should diagnose the fault and react.

Fault: The Demand Addition Valve is NOT adding gas
GEM Reaction: You will not hear or feel the valve adding gas and since it is not adding, the volume of gas in the loop will get smaller on every breath and you should notice that there is less volume in the loop to breathe!
Your Diagnosis: Check to see there are still bubbles exhausting from the mouthpiece. If so, then it is not likely a problem with the mouthpiece. Check your SPG and confirm you have plenty of gas in your cylinders and the valves are on. If the mouth piece is exhausting bubbles and your valves are on and you have plenty of gas in your cylinders, then the problem must be the ADD VALVE.
Your Reaction: You have two different correct responses to this situation. 1. You can add gas to the loop manually (if you have the manual add) thus essentially bypassing the demand valve. This is a fairly natural fault correction technique because if the volume of the loop gets low (the system is harder to breathe) you simply add more gas. The GEM will release excess gas if you add too much. 2. Close the GEM mouthpiece and bail out to the open circuit system and abort the dive.

Fault: The demand valve is free flowing
GEM Reaction: The loop is at maximum volume and gas is bubbling around your lips and the mouthpiece. You can also hear the auto demand valve adding continuously.
Your Diagnosis: There is a free flow in the automatic demand valve.
Your Reaction: Disconnect the quick connect fitting to the automatic demand valve. This will stop the free flow and save any gas that may be lost. At this point you have two options. If you have the optional manual addition valve you simply add gas to the loop as it is needed to maintain volume and abort the dive. Or you can bail out to the open circuit system.

Fault: The scrubber is flooded
GEM Reaction: If excess water has collected in the scrubber chamber you will experience resistance to inhalation because of its design. The resistance is caused by your trying to draw gas through the water in the chamber. The water in the chamber will inhibit the removal of CO2 by the scrubber and you may also notice the signs of hypercambia, or increased levels of CO2 in the loop. This is usually experienced as abnormally fast breathing and/or head ache.
Your Diagnosis: If the VOLUME of the loop seems to be normal but breathing resistance is noticeably more difficult and the Automatic Demand valve is adding gas as normal, then the most obvious culprit is a failure of the scrubber to remove CO2.
Your Reaction: The only solution to this problem is to close the re-breather mouthpiece and bail out to open circuit and abort the dive.

Fault: Too much CO2 in the loop
GEM Reaction: The GEM will seemingly function in a normal manner. However, you should notice changes in your body. Your breathing rate will increase abnormally and out of proportion with the workload. You may also develop a severe headache.
Your Diagnosis: If the GEM is functioning normally and breathing difficulty has not changed the most logical assumption is that your physical symptoms are due to abnormally high CO2 in the loop.
Your Reaction: The only acceptable solution is to bail out to the open circuit system, at least until you find the cause of the problem. This fault can be caused by several different agents. First of all you could be under a very heavy work load and overpower the scrubber by a rapid rate of respiration. Second, you could have neglected to log the amount of time on your scrubber material and it is no longer removing CO2 from the breathing loop. Third, the scrubber material could have been dated and past its intended shelf life when you loaded it. Fourth, during transportation (or for some other reason) the scrubber material has developed channels that allow a large amount of exhaled gas to go through untreated. The best solution is to bail out, abort the dive and find out the nature of the problem!

GEM Fault and Solution Table
Fault - Diagnosis -> Action
Mouthpiece is NOT Exhausting - No bubbles, System not adding gas -> Bail out and abort dive*
Demand valve NOT adding gas - Volume of gas getting smaller, mouthpiece exhausting normally -> Bail out and abort dive*
Demand valve free flowing - Loop at overfill volume, gas bubbling out mouth -> Bail out and abort dive*
Scrubber flooded - Abnormal breathing resistance, symptoms of excess CO2 in the loop -> Bail out and abort dive
Too much CO2 in the loop - Abnormally fast breathing, headache -> Bail out and abort dive

* After taking the technical course you will have other action options to correct the fault.
Gas Reserves
When diving with the GEM you must base gas reserves on the actual amount of gas in your cylinders NOT on the extended gas available in the loop. The best way to correct a problem in most circumstances (and the only option with flooded scrubber or too much CO2) is to bail out to the open circuit system. So, at any point in the dive you must be able to switch to open circuit and have enough gas to abort the dive safely. For open water recreational diving in a familiar area 700psi as read on your SPG will probably be adequate. Even though you will effectively have 2100 psi of gas through the loop you can not be assured that the loop will function normally! Reserve more gas when conditions are more difficult, the dive is deeper or the diving area is not as well known.

Decompression
Do not practice staged decompression on the GEM unless you are certified in that area and have taken the GEM technical certification course. In addition you must use air tables or air computers for decompression calculations when making no decompression dives.

GEM Assembly
1. Pack the scrubber - Open the lid of the scrubber chamber and fill the compartment with your choice of scrubber material. Fill the scrubber in stages adding scrubber material then tapping the side of the housing to tamp the material, then add more scrubber material and repeat until the scrubber is full. Remove the "O" ring from the housing lid and make sure it is clean, then replace the "O" ring and close the container. If you must transport a loaded scrubber, keep the scrubber container vertical during movement.
2. Attach the scrubber to the mounting system. If you have the integrated weight system or other buoyancy system attach it now.
3. Attach the intermediate hoses to the scrubber and counter lungs. Anytime you are attaching hoses make sure they are secure.
4. Attach the counter lungs to the harness system.
5. Attach primary breathing hoses. Now is also a good time to attach and/or adjust primary hose weights.
6. Attach gas supply. Use the quick connect fitting to securely attach the starting gas supply to the automatic demand valve.
7. Ready all stage bottles or other gas supply. Rig each stage bottle with a first stage regulator that has a hose with quick connect and an SPG.
8. Turn the starting air supply on. Open fully the valve(s) of the bottle(s) that will be the starting gas supply.
9. Take a few breaths off of the GEM then Close the mouthpiece. You are checking the system to see if it will hold pressure. DO NOT CONTINUE BREATHING ON THE LOOP!

Pre-dive Safety Check
When suited up and ready to dive check or have your buddy check the following for proper operation:
W - Wings-check that you can inflate and deflate your wings or buoyancy control system. Take a few breaths off the open circuit bail out regulator to make sure it works.
A - Addition Valve-Make sure the starting gas supply is connected securely to the Automatic Demand valve
L - Leak Out-Submerge your primary and stage bottles (if any) and check for gas leaks anywhere in the system.
L - Leak In-Check the scrubber for leaks. Insure that water has not entered.
S - Safety Check-Do a standard SCUBA safety or "S" drill.
If you’ve been keeping up that spells WALLS.

[Jay]

Thanks for that info Mike! Sounds like a gem of a breather! :)

[SLIM]

It is a GEM of a rebrether, I have used it for some time and now have about 80 hours with it and about 10 hours below 150 feet. There are many that I have dove with that use other majior NAME brands and are all impresesed with it and how it operates. There are so many things I like about it and that is what got me into it and have become a big proponet of it compaired to others and not hveing to reley on on all the bells and wistles.

Rigt now the training is ofered in a limited time span and locaiton. The class is not all that long and not very difficult, it is mostly a how to set it up, operate it and field clean, and understanding the operation of how a SCR works and to relearn some of bouancy. The class is offered by limited instructors since it is new. I bet for the right price one could be delilvered with training but would have to be more then just 1 person for me to travel. If you travel up to this area it is much easyer to get training.


Remmeber that the designer and manufacture of this unit has sat on a pannel of RB experts such as Bret Hempill, Tom Mount, FW, Gene Melton. Even a few others that you all konw have been very impressedwiththe unit.

SLIM

[rjack]

Thanks for the write-up! Very clear.

For tech dives say 21/35 to 150ft, what deco gases would you bring?

On the gem you have the ppO2 drop, but the deco gas is also bailout deco of course.

[deepairmike]

we would use 50% and 100% there's not as much drop in the o2 as you would think it stays very stable and on deco if you flush the loop every 4th breath there is almost no drop over the suply gas.

[rjack]

we would use 50% and 100% there's not as much drop in the o2 as you would think it stays very stable and on deco if you flush the loop every 4th breath there is almost no drop over the suply gas.

Ahhh perfect, forgot about the deco loop flushes already! duh

[SLIM]

Yup, I dive a 20/30 mix an a regular basics in one of the local caves and use 50% and 100% for deco. I have a sensor that I use and both Deepairmike and I made some print outs and found the drop is not all that bad and once you do a flush it is perfect. Then there is the mouthpeice that I have that allows me to move it a notch for deco to help out. Remember if I use 100% my discharge is less CO2 and then I can still flush but still have a large amount of O2 in my loop that saves gas from my tanks.

SLIM

[Tegg]

pics?:smt102

[FW]

This is the older sidemount version. The valves for gas release have been moved to the mouthpiece in the new version.


http://www.cavediver.net/forum/gallery/files/8/gem3_thumb.jpg (http://www.cavediver.net/forum/gallery/files/8/gem3.jpg)

http://www.cavediver.net/forum/gallery/files/8/gem4_thumb.jpg (http://www.cavediver.net/forum/gallery/files/8/gem4.jpg)

http://www.cavediver.net/forum/gallery/files/8/gem1_thumb.jpg (http://www.cavediver.net/forum/gallery/files/8/gem1.jpg)

http://www.cavediver.net/forum/gallery/files/8/gem2_thumb.jpg (http://www.cavediver.net/forum/gallery/files/8/gem2.jpg)

There is a picture of the backmount version in deepairmike's avatar.

[rjack]

Yup, I dive a 20/30 mix an a regular basics in one of the local caves and use 50% and 100% for deco. I have a sensor that I use and both Deepairmike and I made some print outs and found the drop is not all that bad and once you do a flush it is perfect. Then there is the mouthpeice that I have that allows me to move it a notch for deco to help out. Remember if I use 100% my discharge is less CO2 and then I can still flush but still have a large amount of O2 in my loop that saves gas from my tanks.

SLIM

For your O2 monitoring, which ratio mouthpiece do you have? What kinds of ppO2 drop are you experiencing?

[Arnold Mesiser]

This master plumber approves of your piping :)

[SLIM]

I do not have much of a ppo2 drop, the mouth peice I have has 2 positions. THe dive spot is a 8:1 and the second is a 16:1 ratio. To be honost, I have forgotten wich one I have. I have been through a few of them and tried them but right now, I think I could be worng. Funny how Mike can keep it all straight.

Good pics there FW, I keep saying one day I will get a new dig camera and get some pics of mine. In time, in time. SHould have had SSK do them when she was up.


SLIM

[deepairmike]

For your O2 monitoring, which ratio mouthpiece do you have? What kinds of ppO2 drop are you experiencing?

I am useing a 20-1 mouthpiece at 5' deep 36% drops to 22% but by the time you get to 80' there is only a 1% drop. At 250' if you flush the loop there is no noticable rise in O2. You just don't consume anywhere near what you put in

[fire diver]

I am useing a 20-1 mouthpiece at 5' deep 36% drops to 22% but by the time you get to 80' there is only a 1% drop. At 250' if you flush the loop there is no noticable rise in O2. You just don't consume anywhere near what you put in

I talked to SLIM about the GEM, and I like the idea of it. I understand it is a very simple design, but does it have O2 sensors built into the loop, or can that be added easily?

[daehag]

Here's some shots for FW's SM unit.

http://daehagkim.com/wordpress/wp-content/gallery/Forest%20Wilson%20Sidemount%20Rebreather%20at%20De vils%20Eye/Forest%20at%20Devils%20Eye.jpg

http://daehagkim.com/wordpress/wp-content/gallery/Forest%20Wilson%20Sidemount%20Rebreather%20at%20De vils%20Eye/Forest%20Siemount%20Rebreather%20at%20Devils%20Eye .jpg

http://daehagkim.com/wordpress/wp-content/gallery/Forest%20Wilson%20Sidemount%20Rebreather%20at%20De vils%20Eye/Forest%20Sidemount%20Rebreather%20at%20Eye.jpg

http://daehagkim.com/wordpress/wp-content/gallery/Forest%20Wilson%20Sidemount%20Rebreather%20at%20De vils%20Eye/Forest%20Sidemount%20Rebreather01.jpg

[Arnold Mesiser]

Spectacular photos!! Thank you for sharing them!!

[FW]

Thanks Daehag, I was never able to get them to look that good.

FWIW, that is the RB I built, not the GEM. Mine uses a separate O2 bottle, and a "Kiss" style injector system.

[Gary]

FWIW, that is the RB I built, not the GEM. Mine uses a separate O2 bottle, and a "Kiss" style injector system.

:)

That's my idea!

I was about to mention that to Mike in case he missed me talking about it on RBW.

How you liking it FW?

Kathleen and I are going to get Mike to built us some if he will.

How aout it Mike?

[Squirrel Girl]

Gorgeous pictures, Daehag!

[MichaelAngelo]

Mike You getting me awfly excitied about Mo cave diving again. Sitting in Cleveland till next week. Still up for Monday the 17 th?
MA

[FW]

Mike You getting me awfly excitied about Mo cave diving again. Sitting in Cleveland till next week. Still up for Monday the 17 th?
MA
I would say that is a safe bet. See this thread, post #5 :-)

http://www.cavediver.net/forum/showthread.php?t=10939

[deepairmike]

Mike You getting me awfly excitied about Mo cave diving again. Sitting in Cleveland till next week. Still up for Monday the 17 th?
MA

I am so ready!!!! Can't wait!!!

[mwenner]

Thanks Daehag, I was never able to get them to look that good.

FWIW, that is the RB I built, not the GEM. Mine uses a separate O2 bottle, and a "Kiss" style injector system.

Real nice photo's, in nice cave (where?). Those are the best shots of your SM system I've seen Forrest. Could have used a better model (diver). Wish we had Aug. 17th free, because now I'm getting excited! Might have to wait until Sept.

[FW]

Real nice photo's, in nice cave (where?).
Devil's Eye

[deepairmike]

anyone interested in seeing the GEM in person and perhaps diving with it. Adam will be heading to cave country soon and can demo. If we get a group and location lined out in advance?

[MichaelAngelo]

anyone interested in seeing the GEM in person and perhaps diving with it. Adam will be heading to cave country soon and can demo. If we get a group and location lined out in advance?

I just dove the GEM and recommend it.

[sskasser]

anyone interested in seeing the gem in person and perhaps diving with it. Adam will be heading to cave country soon and can demo. If we get a group and location lined out in advance?

me!! Me!! :d

[Slüdge]

How about two days of demo? For instance, a Saturday at Jackson Blue and Sunday at Peacock.

[Gary]

I'd like to see it - anywhere from High Springs to Lauriville.

[SLIM]

Notice how everyone wants us to come down and show it off and they don't want to come up here to see it.

SLIM

[FW]

Notice how everyone wants us to come down and show it off and they don't want to come up here to see it.

SLIM
Hey, not *everyone*!

[sskasser]

Notice how everyone wants us to come down and show it off and they don't want to come up here to see it.

SLIM

Yeah, what Forrest said...not EVERYONE! SOME of us have been up there to see it :smt079

[scubadam67]

How bout the weekend after labor day? and i'll let ya'll choose the spot it will be up to SSK she is going to be the driver so tell her where you want me and the GEM

[Slüdge]

For years, the first weekend after Labor Day was the first weekend we could dive Jackson Blue in three months, so we always had a dozen or so divers meet on Saturday. We could continue the tradition...

[sskasser]

That works for me.

[FW]

Works for me too, since there may be an NSS-CDS board meeting in Marianna that weekend.

[scubadam67]

sounds like we have a plan then i'll start packing. i think i may try and bring 2 the standard unit and the newest sidemount unit. what do you think mike?

[deepairmike]

sound like a plan

[Tegg]

Works for me too, since there may be an NSS-CDS board meeting in Marianna that weekend.

according to the website the next BOD meeting is Nov 6th at DEMA? :smt102

[FW]

according to the website the next BOD meeting is Nov 6th at DEMA? :smt102
I said "may be". When it is official, it will go on the website, stay tuned.

[Swede]

...and the newest sidemount unit...

Please!!! take alot of picture of the SM unit and put on the web... I want to se how this looks like (it's a bit of a drive from Sweden...:smt013)

[sskasser]

I will be taking LOTS of pictures. Are you sure you don't want to run over here from Sweden, though? ;)

[FW]

Please!!! take alot of picture of the SM unit and put on the web... I want to se how this looks like (it's a bit of a drive from Sweden...:smt013)
I will give you access to the DIY rebreather forum. There pictures of the prototype there.

[deepairmike]

I have some photos of Forrest on the new sidemount unit at Jackson blue I will e-mail them tonight

[FW]

I have some photos of Forrest on the new sidemount unit at Jackson blue I will e-mail them tonight

Here is the picture of me in the sidemount GEM. Notice how compact it is. The hoses can be stuffed inside for transport. It needed a little more weight to keep it level with my lungs.

[Swede]

I will give you access to the DIY rebreather forum. There pictures of the prototype there.

Thanks... I check them out...

a safe SM unit would be the only way I would start RB diving...



sskasser... I'm sure I want to run over there, it's just not about that :roll:

deepairmike... If you can/want, you can email them to markus@nordproduktion.se

[Attchoum]

since im pretty sure there will not be demo in mexico, can i also have acces to that diy forum??

Im pretty happy about my revo but im currious about a sidemount unit.

[FW]

since im pretty sure there will not be demo in mexico, can i also have acces to that diy forum??

Im pretty happy about my revo but im currious about a sidemount unit.
I posted a picture of the new sidemount unit above, but I will give you access to the DIY forum as well.

[scubadam67]

I will be in mexico off and on all winter so there could be a demo set up in the area. i will be in cozumel in oct. for a week then i am going to try and stay for all of jan. feb. and i was thinking of bringing my gem with me if you can get some interest i would be happy to see if we can work out a time and place.

[sskasser]

Here's a picture of Mike and Forrest with the newer sidemount version, at the 2009 NSS-CDS Workshop in Tallahassee.

http://www.cavediver.net/forum/gallery/files/1/7/2/2/pict0098.jpg

[FW]

Here's a picture of Mike and Forrest with the newer sidemount version, at the 2009 NSS-CDS Workshop in Tallahassee.

Too bad the hoses aren't on it in the picture. That is what it looks like with the hoses inside for transport.

[sskasser]

Just 12 more days...I'm looking forward to seeing everybody!

[Gary]

For years, the first weekend after Labor Day was the first weekend we could dive Jackson Blue in three months, so we always had a dozen or so divers meet on Saturday. We could continue the tradition...

So the 12th? At Jackson Blue?

What time?

[FW]

So the 12th? At Jackson Blue?

What time?
I *think* it is around 10:30. I will be there earlier, you can look at mine too :-)

[Slüdge]

The P&R guy still hasn't gotten with Edd - he'll let us know today or tomorrow if we can have a pavilion and if we'll have to pay for it. I figure if we have to pay we can get everybody to chip in two or three bucks apiece.

[BobK]

I think I'd like to go too !

[FW]

I think I'd like to go too !
Come on down! (Er, up) :-)

[sskasser]

I think I'd like to go too !

Awesome! See you there!!

[scubadam67]

sounds like we got a good group coming can't wait to get there. i just got out of 61degree water with 6 to 8' of vis hope ya'll will show me at least that.

[icestac]

sounds like we got a good group coming can't wait to get there. i just got out of 61degree water with 6 to 8' of vis hope ya'll will show me at least that.

Only 68 degree water and 8+ foot vis ;)

Make sure you wear your big fins in JB, you'll need em.

Cheers,
Jeff

[FW]

Only 68 degree water and 8+ foot vis ;)

Make sure you wear your big fins in JB, you'll need em.

Cheers,
Jeff
I am bringing my SS "fins", and my long duration "stage bottle" :-D

[scubadam67]

yep just got in a new set of hollis fins so i guess it will be a good test for them

[sskasser]

I am definitely not a photographer, but I did snap a couple of shots of the G.E.M. and the demos. I had a lot of fun on my test run! Bouyancy....hmmmm, yeah, it's a little different from OC :rollguy

http://www.cavediver.net/forum/gallery/files/1/7/2/2/pic_0044_513322.jpg

http://www.cavediver.net/forum/gallery/files/1/7/2/2/adam_mark_gem.jpg

I'll put some more in the Photo Gallery, so go have a look.