Rebreathers (CCR) What Recreational divers need to know

[bowlofpetunias]

Thanks for the explanation . I actually followed that pretty well and had a bit of an idea what I was seeing in the video which is great.
Clearly the gold standard would be a well informed buddy pre dive. Perhaps now is a good time to try to come up with a list of Recommended Questions an OC should ask or have answers to if diving with a CCR diver?

 

[doctormike]

Thanks for the explanation . I actually followed that pretty well and had a bit of an idea what I was seeing in the video which is great.
Clearly the gold standard would be a well informed buddy pre dive. Perhaps now is a good time to try to come up with a list of Recommended Questions an OC should ask or have answers to if diving with a CCR diver?

Yeah, maybe sweep through the thread and just collect the various points...

 

[KenGordon]

If he doesn't respond I will look for a bail out lever or button like in the picture

NO! NO! NO!

That will drown many CCR divers. Unless it is your buddy and you have been briefed then do not attempt a bailout.

If the diver is montionless and non responsive then they need help. If they are having a problem and require not to be distracted then there is likely to be motion - checking the handset, adding or dumping gas, whatever. If they are just lying on the bottom looking out of it then ask ok?

This thread seems interesting and informative but actually is slightly scary. A little knowledge is a dangerous thing and all that...

Unless you have a CCR buddy you will never need to go to a CCR diver for gas. If you claim otherwise then you are not diving sensibly wrt your own buddy and should fix that.

If you have to give aid to a CCR diver then the chances are bad. You may make them worse. If that bothers you then find a CCR instructor and spend some time learning how to help.

Most of the time I dive with OC divers. They can all come to me for gas but I have little expectation that they can help me even if I explain how. In fact even with other CCR divers I know how hard it is.

Dive management, when assigning buddy pairs, should avoid landing an OC diver with a CCR buddy unless that OC diver is familiar with buddying CCR divers.

 

[bowlofpetunias]

Seriously Ken that may need to be the take away message from this thread.

To be perfectly clear you can never say anything is impossible. 800 plus bottom hours is still a newbie to some divers on SB. I would say that since I have well over 800 hours and have never EVER came close to going OOA the chances of me doing so is incredibly remote. Our gear is very well managed and serviced regularly. Gear failure can still occurr and cause an OOA situation but again less likely with well maintained good quality gear. I am selective of my dive buddies and buddy procedures are a real sticking point with me. I am getting more entrenched in my attitudes about these as the years go by.

Unfortunately in the distant past I dived with a CCR diver in our group and I didn't know what I didn't know back then. I had no idea that I could not count on that diver for air sharing. I should have insisted that I get a brief on the unit and significance of that CCR but I let the fact that it was an instructor intimidate me. I should have challenged the situation.. I didn't.. I learned and I will never let that happen again.

It seems to me that CCR divers are basically diving solo with someone else who needs to consider themselves also to be a solo diver with someone else. I have no intention of becoming a solo diver so I select my buddies carefully. I don't care how much the trip to the dive site coast me. No dive is worth my life so I will happily sit out a dive if I am not comfortable with the buddy available. Pete can verify that we had a great visit on the boat when he had to sit out the second dive. Even though I had traveled half way around the world I was not willing to get into the water with the divers that were available. No regrets.

This thread is in Basic so other OW divers can learn from my mistakes and even my faulty assumptions here. I want people to call me out here where I am wrong because my misunderstandings probably are similar to other non CCR divers.

We share our recreational shallow sites with CCR divers in increasing numbers. I won't side track this about the significance of CCR dives in shallow water at this point. If I see a CCR diver with red lights flashing and or alarms sounding I will certainly make sure I check to see if he is responding. If I see bubbles coming from a CCR unit it will get my attention I would likely just watch to see what he is doing. If something looks amiss I will advise him... just like I would a OC diver if I saw bubbles coming from somewhere that didn't look right.

I am neither a hero nor a fool. If I can help I would like to. If I don't know what to do I am not going to start messing with stuff. It may be the best option will be to try to locate anyone diving with them in case they got separated.

 

[bowlofpetunias]

Yeah, maybe sweep through the thread and just collect the various points...

Questions the OC (open circuit) diver needs to ask. Do not interrupt the pre dive check to ask questions.
Can you share air with me if I need it and How does it happen?
What should I watch for.... alarms etc and what should I do if I notice one?
Is there anything I need to watch for in your behavior?
Is there anything I should NEVER touch or do?
What should I do if your mouthpiece comes out and you are not responsive?

Some have said go for the bail out others have said not to:

 

[bowlofpetunias]

The (very very very) basic information an OC diver needs to know diving with a CC diver is:

1)How to identify the presence of a problem.
2)How to react to said problem.
3)Equipment considerations that dictate how to react to said problem.

Each of those points has a myriad of possible answers dictated by the configuration, familiarity of both divers involved, and the method of failure. This goes for problems with either the OC or CC diver. There's no hard rules for this because CCR, by it's very nature, differs quite significantly depending on the dive, the equipment, and the procedure to affect a rescue. Trying to give specifics is sort of a losing battle, because what works for an OC diver with a Poseidon diver, is completely different to an OC diver with a Meg diver, to a JJ diver to a KISS diver to a Revo diver to an SF2 diver. And that goes for the OC diver having an issue too.

Ultimately the answer is the OC buddy just needs to ask the question, "what if something goes wrong" and go from there. Trying to get any more specific than that is just going to try and cover too many "what-ifs" for this thread.

Maybe I should just have quoted this post.. it does make some excellent points clean and simple

 

[bowlofpetunias]

This has been a good thread.

A lot of good information has been provided.

Even as a long time CCR diver, I am not familiar with all units. I would make a point of asking during the briefing.

1. How do I close the mouth piece.
2. Do you have a BOV (as Ken said not all units do), if so, how do I switch it to OC.
3. How do I flush your loop. (Flushing the loop puts clean gas in the breathing loop. This solves low O2, high O2, and CO2 issues - at least in the relative short term.)


Generally. I very, very seldom dive with any diver who is diving on a single cylinder. If my buddy isn't on CCR, then they are normally diving a twinset. Or as an absolute minimum a single cylinder with a pony (or stage). This means that we both are 'self sufficient' at least we can each bailout onto alternate gas initially. How we handle the issue from there is another matter. Under these kind of circumstances we will only be thinking about our exit strategy, even if that includes stops.

Gareth

I am quoting this one as well to bring it forward as it has excellent simple questions as well.

 

[Gareth J]

Two further thoughts.

I have assumed that we are talking recreational limits. i.e No rich mixes, no hypoxic mixes, single bailout cylinder.
i.e. MOD1 level as far as the rebreather diver is concerned. Say 40m max (120ft) possibly with deco.
The type of diving where you roll up at the boat and get given a buddy who you don't know. In this case you want the minimum of complication in the briefing anyway

Personally, for this type of diving I would be either carrying air bailout (because I was lazy sorting gas), its easy to get and no complications.. Or ideally Nitrox 27, because its safe to use for both the CCR diver and anyone else.
I have picked up a cylinder of Trimix bailout before now because that's all I've got available. Generally for me - the deco' penalty is so small who cares. If I do bailout, the computer will sort the stupid mix deco' requirements anyway. Worst case for me is I sit at 6m clearing all my deco' then do the same time again for the nelegible Helium, I can always breath the O2 once back on the boat as well. - The slight issue is my buddy. If I had an OC buddy intending to run +10mins of deco', he would be carrying a rich mix anyway.



IF you are talking deeper than this then everyone needs to be far better prepared and aware. Because you then can have complicated bailout strategies, hypoxic mixes, rich mixes etc. That's a whole different matter.
I would be very dubious diving with a group doing mixed gas who where not far better prepared and briefed as a team. Similarly, I would be cautious diving with an unfamiliar buddy in these circumstances.


First Aid points.
Remember that a CCR makes a good O2 set. Or at least, a spare cylinder of O2 which you can attach a regulator too.
(If you are prepared you can have DIN - medical adapters for the O2 kit, which is worth having in the O2 kit anyway.)

Gareth

 

[bowlofpetunias]

I was actually thinking of Basic as No Deco dives. It is natural that members think of the way they dive or the dive sites they normally frequent when they post or or read posts on SB.

I have been fortunate enough to dive in a few places over the years. It is important that we consider all the likely sites that the CCR and the basic OC diver will share on strictly recreational dives. Our local diving tends to be shore diving at some very popular sites. I tend to save my $ and not do boat dives locally even tho there are some decent ones here. I prefer to use the $ when we go on a dive trip for boats in Florida, California, PNG, Indonesia or the GBR sites.

Depending on conditions some sites may be more like diving in a Jacuzzi with all the divers in the water. That is the situation I am concerned with personally. Not saying the ones you run into on boats aren't an issue. It just seems to me there is a better chance that there will be a conversation and agreement before the dive if you are buddies.

Those conversations are really important.. as I said earlier.. the gold standard. I am still concerned that if I run into a CCR diver in trouble that I would have at least the most basic idea of what I should or shouldn't do.

You make a great point about the o2 fittings. I can't remember off the top if I can fit mine to a Din. I will have to check and decide if that is a modification or attachment I should get to potentially extend the amount of O2 available. My system has 2 small cylinders so it can fit in a pellican case. LOL hubby always complains about the amount of First aid gear in the car when we dive. He says I just miss the light bar and siron too much.

 

[Gareth J]

You make a great point about the o2 fittings. I can't remember off the top if I can fit mine to a Din. I will have to check and decide if that is a modification or attachment I should get to potentially extend the amount of O2 available. My system has 2 small cylinders so it can fit in a pellican case. LOL hubby always complains about the amount of First aid gear in the car when we dive. He says I just miss the light bar and siren too much.

Probably for a new thread. But in our club O2 kits we have DIN to medical 2 pin, and Bullnose to medical two pin adapters. see the links Medical cylinder adapters and for you In australia
We regularly use hard boats that have J cylinders of O2 on board, and we have a good mix of Nitrox with us on most trips, from back gas and deco gas, to O2 with CCR units.
It allows us to start with medical O2 (in the O2 kit), then work our way around the boat if these runout before we can medivac the injured diver.

Gareth