Rebreathers (CCR) What Recreational divers need to know

[stuartv]

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.

This comes across as you having an intent to demand (if necessary) a briefing on someone's CCR unit. Unless that person is going to be your actual dive buddy, I am unclear on why you feel as though you would have the right to insist on such a thing.

 

[doctormike]

I think that this thread is suffering from mission creep, and we are coming up with all sorts of unusual scenarios involving hypoxic dil, deco, atypical configurations, etc... I don't think that a once a year single tank vacation diver is going to be instabuddied with someone diving an expedition grade rig doing some major dive.

The point is that it is becoming more and more likely that a vacationing CCR diver who doesn't have a buddy, and who is doing a simple recreational dive, will be buddied with an OC diver. And some basic understanding of the issues involved would make a good sticky. It's not like the OP is recommending a course curriculum which the OC diver will then follow blindly, no matter what his or her buddy says or what gear they are carrying. It's just a starting point to make the pre-dive discussion more useful and understandable. As rebreather divers, we are so immersed in the gear and the language that we may forget that OC divers may have no idea why we have a second scuba unit clipped off to our harness.

Ken, I don't think that Sheila is saying that she would just go up to a motionless CCR diver concentrating on some task and throw the BOV switch. She said "if he doesn't respond". If my buddy really confirms that I am unresponsive to any and all stimuli, I would like him or her to do that and at least give me a chance. Of course, if you feel strongly about that, and you were buddied with an OC diver, you would just tell them not to touch the BOV no matter what. What you say to them before the dive clearly supersedes anything that someone learned once on SB.

 

[JohnnyC]

I think somewhere along the line the OP muddied the waters (and not unreasonably) by moving away from "being buddied with a CCR diver" and moving to "there's a CCR diver in the same water" which is SUBSTANTIALLY different and opens up the gigantic can of worms we're all guilty of adding to. A good case in point was her list. It's not that there was anything wrong with it, but there's a lot of assumption behind it. Even my own preferences in the situation run contrary to my recommendations to others because my situation is different from everyone else's. And there are times where my situation will run exactly to my recommendations, as it is situational and as is any CCR diver diving in a mixed team.

Realistically speaking, regardless of anything else, unless the CCR diver is YOUR buddy, the best course of action is to simply pretend they do not exist, since there are so many potential answers to the questions presented here, and what's appropriate in one situation may not be appropriate in the same situation, given even one different variable (think the simple difference between having a BOV or a DSV, even with all else being equal).

Since it's the basic forum, I think OP needs to concentrate on one issue at a time. In this case, I think she needs to approach it as solely the situation of being buddied with a CCR diver. Everything else should cease to exist until she has reached that point of knowledge and experience to understand the issues and broaden her perspective in other situations.

 

[stuartv]

I think that this thread is suffering from mission creep, and we are coming up with all sorts of unusual scenarios involving hypoxic dil, deco, atypical configurations, etc... I don't think that a once a year single tank vacation diver is going to be instabuddied with someone diving an expedition grade rig doing some major dive.

Well... My CCR buddy and I dived the Oriskany a few months ago. There was one other tech diver on the boat and everyone else were single tank, OC, recreational divers. My buddy intended to go to the bottom (215') at some point during our dive. So, he was setup with hypoxic dil and was carrying 2 slung cylinders (1 bottom mix and 1 deco gas). The rec divers would be exploring the ship's tower which starts at around, roughly 80 feet.

If I had turned up sick one morning or something like that, he still would have been out on that boat, guaranteed.

All it takes is a dive site with stuff to see at a lot of different depths (e.g. a wall dive, a reef with a lot of relief, or... an artificial reef with a lot of relief).

I'm not saying he would have taken on an insta-buddy in that situation. But, who really knows what kinds of setups people will find themselves sitting next to on a boat?

Anyway, as I have been saying since the start of this thread. The only simple answer is a pre-dive conversation. Beyond that, it's the same as it always is. Every diver has to use their best judgment based on the info they have at the time. But, if an OC diver comes upon a CCR diver in the water and thinks about touching ANYTHING on that diver's rig, they better be absolutely positive that the alternative is worse.

In the face of ignorance regarding the diver's rig, it seems to me that all you can do is verify they are (really and truly) unresponsive or, possibly, simply out of their gourd (narced? panicked? having a heart attack?), and, in that case, get them to the surface in a controlled fashion. But, you better be SURE that the alternative is worse before you physically take control of another diver and force them to the surface. And you also better be SURE that you can do it without endangering yourself. Don't turn 1 statistic into 2.

An alternative to being sure and taking control of them would be, circumstances permitting, keep your distance and shoot a bag. Keep an eye on them and hope the boat crew is alert enough to send help when they see your bag. Keep yourself safe (including minding your own gas level and NDL), no matter what.

 

[mdb]

Dive solo.

Stay from any group huddle.

That has been my MO for many years.

Peaceful, serene, relaxing diving. That is what I am looking for.

Save the Drama for your Mama.

 

[lowviz]

@mdb Exactly. But diving solo brings up a very similar issue.

1) recreational solo diver OOG
2) recreational solo diver happens upon a nonresponsive CCR diver.

What's a mother to do? For me, after thoroughly following this thread, I would present myself to a CCR diver showing my SPG and slashing at the neck. The rest is up to the CCR diver.

In the other scenario, I would just assume the CCR diver is breathing something toxic. Thus, I would attempt to put him/her onto my back gas and begin a proper ascent while hoping for a miracle.

Feel free to correct my thinking.

 

[RainPilot]

Thus, I would attempt to put him/her onto my back gas

Removing the loop from an unconscious divers mouth is risky at best. Chances of water aspiration and drowning are VERY high. The only real way to get them on a breathable gas is to switch to their BOV if they have one.

Something to consider also when rescuing a CCR diver is the possibility of convulsions. You need to be very careful not to put yourself in a situation where their violent convulsions may put you in danger.

 

[mdb]

@mdb Exactly. But diving solo brings up a very similar issue.

1) recreational solo diver OOG
2) recreational solo diver happens upon a nonresponsive CCR diver.

What's a mother to do? For me, after thoroughly following this thread, I would present myself to a CCR diver showing my SPG and slashing at the neck. The rest is up to the CCR diver.

In the other scenario, I would just assume the CCR diver is breathing something toxic. Thus, I would attempt to put him/her onto my back gas and begin a proper ascent while hoping for a miracle.

Feel free to correct my thinking.

Good questions lowviz.

I do not have the answers.

If I OOG for whatever reason(s), equipment failure etc. I would hope to just make a free ascent.

It is very hard to foretell what you would really do.

I have been diving mostly solo for many years.

If on a boat dive, I normally get in quick and early or wait until the rest of the boat has splashed.

I want to peacefully see the environment, no bubbles-except mine.

 

[lowviz]

Removing the loop from an unconscious divers mouth is risky at best. Chances of water aspiration and drowning are VERY high. The only real way to get them on a breathable gas is to switch to their BOV if they have one. ...//...

I was taught to work on an NR (nonresponsive) diver from behind to minimise sustaining an injury from convulsions or the complications that a freshly awakened panicked diver may present.

Going to the BOV just starts us chasing our tails again. What should a CCR ignorant OC diver do if one ever happens upon an NR CCR diver? Send him/her up on a bag?

 

[doctormike]

Going to the BOV just starts us chasing our tails again. What should a CCR ignorant OC diver do if one ever happens upon an NR CCR diver? Send him/her up on a bag?

Forget about happening upon a diver. That's a very unlikely scenario, and not the main point of this thread. We are talking about a discussion that should occur before a dive with a mixed OC/CCR buddy team. I don't dive a BOV, but if I did, and if my OC buddy found me actually unresponsive, I would absolutely want him or her to hold the loop in place and throw the switch.