BCD air, cool discussion by Crowley

[fisherdvm]

EDIT: Actually the post was started by Steve50

But it is in the instructor's panel, and we can't participate.

His question posed by a student, was can you breathe air from your BC.

My question is, if you are doing CESA, you might be better not trying it? If you had a little water in your BC inflator hose, it might choke you, cause your larynx to close, just as you approach the most dangerous part of your ascent, the top 10 or so feet, when your lung is expanding the quickest. It might cause a successful CESA to become an unsuccessful one?

But I guess if you held the inflator button open and wait till bubbles to come out, then it might be safe. But who is going to think of this when you are doing a CESA??

 

[dkktsunami]

If you hold the inflator button open your ascent will be more "missle-like" than controlled. You probably mean the deflate button.

 

[fisherdvm]

Hey, you're out of air right? But that would be cool too!

 

[dkktsunami]

Hey, you're out of air right? But that would be cool too!

Not entirely awake here. I would have figured that out in a couple more hours.

 

[boat sju]

We discussed this in my ow class back in the early 80's. I've been curious as to why I haven't seen it discussed here before. There was a concern as to what bacteria might be growing in the bc bladder so we never tried it though.

 

[saltydawg]

not to mention the chemicals in the bladder it's self that may be harmful in ppm at depth

 

[String]

Some BCs are designed to be easy to breathe from for this reason. Better infection than dead.

The AP valves/buddy range which probably make up 75% of divers kit in the uk are designed with it.
However, people dont train it so i suspect in a real situation they'd get it wrong.

Its something that was taught here but dropped like buddy breathing and cesa due to being potentially dangerous and dated.

Way the obsession with cesa anyway?

 

[Cheekymonkey]

Yea it can be done, just not healthy, its another last ditch choice

 

[DavidPT40]

I've seen it discussed here before. One guy even commented that he did a 3-minute safety stop while breathing from his BC.

If someone could comment, as the percentage of oxygen drops in the BC (since you are breathing it), and is replaced by carbon dioxide, is your body still able to utilize the lower percentage oxygenated air?

 

[Charlie99]

If someone could comment, as the percentage of oxygen drops in the BC (since you are breathing it), and is replaced by carbon dioxide, is your body still able to utilize the lower percentage oxygenated air?

Yes, up until you pass out and the BCD mouthpiece falls out of your mouth.

Many rebreather accidents are essentially that --- there is a problem with the O2 injection (or the tank valve is turned off), the diver continues to rebreathe his air with lower and lower FO2 up to the point where he passes out.