Using your BCD for out of air emergency

I get all the diving magazines and my favorite and in my opinion the most unbiased and authoritative one is "Undercurrent" because it accepts no advertising and is not beholden to any mfr. or agency to subsidize it's publication.

The January 2008 issue has an article called "Out of Air-Try your BCD" which is a fascinating and potentially lifesaving strategy.

You can go to undercurrent.org and see if you can access the article because some articles are available to non-members.

It basically explains that "as a last resort........if your tank is empty at depth you can get some air through your regulator as you ascend and whatever air remains in your tank expands. Once your tank is bone dry, you'll still have residual air in your BCD or at least in your inflator hose. If you added air with your power inflator it will contain 21 % oxygen. If you orally inflated your BCD it will still contain at least 16 % oxygen.............."

This technique is not without it's potential hazards and requires practice in order to master it but it sounds like it's good to know about in a life threatening situation.

Comments, amigos?

Sy

This one comes up every few months and as you quoted may be a "last resort" technique.

I love this crap,"whatever air remains in your tank expands". The air in the cylinder does not change one iota on ascent. The pressure in the cylinder relative to the external pressure will become greater than the external pressure as the external pressure lessens during ascent.

The trick to practicing it is to convince yourself that your BC bladder is clean enough to to set you up for a nasty lung infection.

Pete

Sounds interesting, but let’s face it, if really left on your own without an alternate air source (i.e. buddy) most would CESA in that situation. I realize the key is never getting into a situation like that in the first place, but if worst case scenario really happened the time trying to get air out this way may have been better utilized doing a CESA. You have seconds to react and the deeper you are the more precious time becomes. I guess getting a pony and practicing with that would make more sense. Just my two cents...

AZ

The other downside to beathing the air out of your BC is you will go negatively bouyant. You might get a breath or two of stale air, but now you have to swim up extra hard. If you can't, you drop your wieghts and do a uncontrolled ascent - ouch!

Hmm, if your BC is not very clean, I wonder if you can rig up an inflator hose for your drysuit, and use your drysuit air instead.

fisherdvm:

Hmm, if your BC is not very clean, I wonder if you can rig up an inflator hose for your drysuit, and use your drysuit air instead.

Click to expand...

Yeah, and you could fart in your dry suit on the way up.

This is something that should never be mentioned. It could come up in someone's mind in an emergency situation and really drive the last nail in his coffin.

And by the way, if it needs practise, how many times can you do it before getting a good fungus lung infection? :11:

Belmont:

And by the way, if it needs practise,....

Click to expand...

And that's the rub. Some of you may be the nerves-of-steel, James Bond-cool in a crisis kind of people. But for me, unless I practice a thing, I'm not confident I'd have the wherewithal to calmly do something I've not trained at while I'm also trying not to soil my drysuit. Which is why my buddies and I drill all the time on the normal emergency procedures, and breathing out of my BC isn't one of them.

When I used to solo a lot, a couple of times a year I'd go out and practice doing a CESA. Going for the surface is a natural response if a person is OOA, so I figured if it hit the fan when I was alone, I might as well be efficient at what I might end up doing anyway. Now that I do some tech diving with a virtual overhead, CESA is not an option, nor is running OOG all alone, so I can't see where breathing from my BC would ever be an option. I dives doubles now and so do most of my buddies, often with stages, so there is usually tons of gas all around if I need it.

Although breathing from the BC is fun to speculate about, I have never heard of anyone using this technique in a real world emergency.