Closed Circuit O2 Rebreathers and Training?

[DiznNC]

Hey guys, brand new, please forgive my ignorance. Been searching this week for any info and can't seem to find jack. Basically what I want to do is practice military style long distance (but shallow depth) underwater compass swims. Yea I am a former jarhead and this is just what blows my skirt up. I know lots of folks consider a O2 rebreather just a toy, because what can you really do with it, other than swim around at 20' like a dork. But bingo, that's exactly what I want to do. So with that in mind, can anybody recommend a simple O2 CCR rig, and any agency/person willing to give you instruction on it?

What I am looking at is the Italian Saonosub AROC96 O2 rebreather, which is essentially the grandson of what Italian frogmen used to sneak under ships and plant limpet mines with (mama-mia!). This is the perfect rig for what I want to accomplish; staying at 15-20', and trying to hit nav targets, such as buoys, or whatever. I am just fascinated by all aspects of navigation, including underwater. And it's a darn good workout as well.

So with that being said, just wanted to throw this out there and see what the hive might think. I know this is probably pretty esoteric (or just plain stoopid) for most; you guys want to go deep and stay long, and for that you need pretty sophisticated rigs and training to go with it. But in my case, I am barely underwater, with a clear and quick bailout right above me. So I don't see why one of these very simple O2 CCR's wouldn't work just fine? (OK, I know, just use OC scuba. Yeah I've done that, but what I really want to is do it with a CCR. Just cuz.)

But here's the rub. They have an O2 gauge, and that's it. I know, I know, OMG. Talk about mCCR, yeah buddy. You have to manually squirt a little O2 into the bag as you motor along (there's a manual fill button right at the tank manifold; the tank is nestled under the bag/scrubber assembly which all sits on your chest.)
So judging by what I've been reading all week, some, if not most (if not all) we be thinking this is just nuts. And I get that; it looks like mainstream rebreather diving is more concerned with using the rigs to go places and do things your OC scuba can't do; so the sophistication that has developed to pull this off, in a safe manner, includes complex diving systems and intense training to learn how to use it. So what I'm trying to accomplish is so far off the beaten path, that many will not understand, including any training agency that might be willing to train me to do this safely.

So with this in mind, any suggestions for a course of action? I am just a PADI OW diver, nothing special but a little OC dive experience under my belt. Is there any agency anyone could recommend for training for this endeavor, and what courses would be a good progression from OC OW to (O2)CCR OW diving?

Full disclosure: retired Marine, still active with reserves/NG; strictly recreational purposes. I can provide references to prove this. Just gotta say that in this day and age I suppose. Any info/ideas greatly appreciated. Thanks!

 

[KevinNM]

If you get it sent to a unit address I would expect it would open up things like the Draege LAR and other modern gear.

 

[rsingler]

Be prepared for some heat from the community.
A lot of heat. Just have a thick skin.
Now that that's out of the way, you need to list your priorities.
If Priority NUMBER ONE is making no bubbles while you practice this skill, then your idea has merit. But then folks really might think you are practicing to set a limpet mine and might be a terrorist. And they won't help you.

If your priority is becoming an absolute Ace at U/W Nav, then duration is a key factor, and again, a CCR might seem to have the advantage. But trust me, as an Instructor who loves U/W Nav, you can really get lost in the 30 min in which you're burning a third of a tank. You won't need 2 hours of dive time to practice this. And if you hit the mark after 2 hours of Nav, you had a) lots of luck, b) no current or c) some terrain nav helping you. Unless you have a SEAL inertial unit unavailable to the rest of us. Even SEALs (used to) surface surreptitiously to check their nav.

But if you really want 2 hours, double tanks and some tech training is all you need. Except you'll be blowing bubbles.

Then there's the expense factor of CCR, including training.
And if you grab an old military O2 breather for cheap? You have age and parts and lack of the latest electronics working against you. CCR used to have 10x the death rate of open circuit. It's gotten better due to checklists and design improvements and electronics.

And then there's safety. But I won't say more than "you can't go below 20 feet!" Because you already know that. But there's hypercarbia if you're working hard in current at PO2 of 1.6. Bad idea. You need to be shallower.

Finally, there's "lung rust". Going long at PO2 of 1.4 (not to mention 1.6) is just unhealthy. In the hospital ICU, we call it ARDS, or Adult Respiratory Distress Syndrome. Just like a piece of iron, oxygen oxidizes things. Including tissue. If you want to repeatedly go long, doing it on oxygen is a bad idea.

Honest to God, you can do exactly this with doubles.

Except you'll be making bubbles that can be tracked.

Sorry to rain on your idea.
I love CCR. I love the quiet. I love that the fish don't even care you're there. I could do Nav for 2 hours as a challenge. Maybe even repeatedly. But I wouldn't do it on pure O2. There is no advantage and lots working against it. But if you go regular CCR to a) not make bubbles, and b) be safer, the costs may be more than you anticipated.
PM me if you want to discuss more.

Diving CCR Doc
(And 21 year military and Hyperbaric Medicine Doc, even if it's the ChAir Force)

 

[Jack Hammer]

Be prepared for some heat from the community.
A lot of heat. Just have a thick skin.
Now that that's out of the way, you need to list your priorities.
If Priority NUMBER ONE is making no bubbles while you practice this skill, then your idea has merit. But then folks really might think you are practicing to set a limpet mine and might be a terrorist. And they won't help you.

If your priority is becoming an absolute Ace at U/W Nav, then duration is a key factor, and again, a CCR might seem to have the advantage. But trust me, as an Instructor who loves U/W Nav, you can really get lost in the 30 min in which you're burning a third of a tank. You won't need 2 hours of dive time to practice this. And if you hit the mark after 2 hours of Nav, you had a) lots of luck, b) no current or c) some terrain nav helping you. Unless you have a SEAL inertial unit unavailable to the rest of us.

But if you really want 2 hours, double tanks and some tech training is all you need. Except you'll be blowing bubbles.

Then there's the expense factor of CCR, including training.
And if you grab an old military O2 breather for cheap? You have age and parts and lack of the latest electronics working against you. CCR used to have 10x the death rate of open circuit. It's gotten better due to checklists and design improvements and electronics.

And then there's safety. But I won't say more than "you can't go below 20 feet!" Because you already know that. But there's hypercarbia if you're working hard in current at PO2 of 1.6. Bad idea. You need to be shallower.

Finally, there's "lung rust". Going long at PO2 of 1.4 (not to mention 1.6) is just unhealthy. In the hospital ICU, we call it ARDS, or Adult Respiratory Distress Syndrome. Just like a piece of iron, oxygen oxidizes things. Including tissue. If you want to repeatedly go long, doing it on oxygen is a bad idea.

Honest to God, you can do exactly this with doubles.

Except you'll be making bubbles that can be tracked.

Sorry to rain on your idea.
I love CCR. I love the quiet. I love that the fish don't even care you're there. I could do Nav for 2 hours as a challenge. Maybe even repeatedly. But I wouldn't do it on pure O2. There is no advantage and lots working against it. But if you go regular CCR to a) not make bubbles, and b) be safer, the costs may be more than you anticipated.
PM me if you want to discuss more.

Diving CCR Doc

This ^

 

[rjack321]

I am (also) worried about you working hard swimming for extended periods of time at pretty high ppO2s. While 15ft is "only" 1.3, 20ft is already 1.6. I would suggest taking OC nitrox and learning a bit more about the hazards of oxygen. 2 hours at a ppO2 of 1.5 or 1.6 is not going to end well.

Physiology wise this plan has a high risk of seizure or pulmonary lung damage.

 

[happy-diver]

Apparently there's a guy that built this unit in his laundry
Pure o2 in the photo, clip an extra bottle to it and it's not
It is brilliant bumbling around in 6m, for 1hr using 40 bar
At least it wasn't an outside dunny like another guy here

I found the engineering drawing

and if you monitor o2 and start off with a lung full of air who knows what can happen

There was an ARO C96 for sale a couple of weeks ago. I bought a C.O.D.E. a while back


These are handy, good looking too
https://en.ccrtriton.com/ccr-triton-tek




Google can be your friend, it's all there

 

[KenGordon]

Hey guys, brand new, please forgive my ignorance. Been searching this week for any info and can't seem to find jack. Basically what I want to do is practice military style long distance (but shallow depth) underwater compass swims. Yea I am a former jarhead and this is just what blows my skirt up. I know lots of folks consider a O2 rebreather just a toy, because what can you really do with it, other than swim around at 20' like a dork. But bingo, that's exactly what I want to do. So with that in mind, can anybody recommend a simple O2 CCR rig, and any agency/person willing to give you instruction on it?

What I am looking at is the Italian Saonosub AROC96 O2 rebreather, which is essentially the grandson of what Italian frogmen used to sneak under ships and plant limpet mines with (mama-mia!). This is the perfect rig for what I want to accomplish; staying at 15-20', and trying to hit nav targets, such as buoys, or whatever. I am just fascinated by all aspects of navigation, including underwater. And it's a darn good workout as well.

So with that being said, just wanted to throw this out there and see what the hive might think. I know this is probably pretty esoteric (or just plain stoopid) for most; you guys want to go deep and stay long, and for that you need pretty sophisticated rigs and training to go with it. But in my case, I am barely underwater, with a clear and quick bailout right above me. So I don't see why one of these very simple O2 CCR's wouldn't work just fine? (OK, I know, just use OC scuba. Yeah I've done that, but what I really want to is do it with a CCR. Just cuz.)

But here's the rub. They have an O2 gauge, and that's it. I know, I know, OMG. Talk about mCCR, yeah buddy. You have to manually squirt a little O2 into the bag as you motor along (there's a manual fill button right at the tank manifold; the tank is nestled under the bag/scrubber assembly which all sits on your chest.)
So judging by what I've been reading all week, some, if not most (if not all) we be thinking this is just nuts. And I get that; it looks like mainstream rebreather diving is more concerned with using the rigs to go places and do things your OC scuba can't do; so the sophistication that has developed to pull this off, in a safe manner, includes complex diving systems and intense training to learn how to use it. So what I'm trying to accomplish is so far off the beaten path, that many will not understand, including any training agency that might be willing to train me to do this safely.

So with this in mind, any suggestions for a course of action? I am just a PADI OW diver, nothing special but a little OC dive experience under my belt. Is there any agency anyone could recommend for training for this endeavor, and what courses would be a good progression from OC OW to (O2)CCR OW diving?

Full disclosure: retired Marine, still active with reserves/NG; strictly recreational purposes. I can provide references to prove this. Just gotta say that in this day and age I suppose. Any info/ideas greatly appreciated. Thanks!

Various nitrox, deco, accelerated deco and CCR courses go into the limits imposed by oxygen exposure. With long accelerated deco, nitrox dives close to MOD and CCR dives this can be the limiting factor. Go too long and you risk a fit. Your other non obvious risk is CO2 poisoning and then how CO2 buildup can make the O2 fitting risk worse.

If you really want to do this without bubbles then get a CCR with dil and get trained for diving that. It could be a simple mCCR or an electronic one. Then you’d learn all this stuff about the limiting factors, how to fill a scrubber, how long a scrubber lasts, etc etc.

Then, if you want to dabble with pure o2, you will be better informed. You will also have a ticket that let’s people sell you pure o2 without worrying you might not have a clue about it.

 

[Tug]

I agree with everything posted above but figured I’d let you know of one commercially available O2 rebreather.

RD1 Oxygen Rebreather

 

[happy-diver]

Really smart guy Michael lombardi
I really recommend buying his book

 

[OceanOpportunity]

Really smart guy Michael lombardi
I really recommend buying his book

https://amzn.to/2U6rpGe