But how are you going to deal with inflated bc underwater other than tie yourself to something?
And while we are building a scenario what are you doing down there breathing in and out of your bc are you waiting for your buddy are you trying to make your way out?
If the gas in your lungs is shifted to the gas in your wing, do you go up, down or stay neutral?
And HELL NO, I'm not waiting for my buddy. I'm swimming out.
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Well, if you are going into %% of oxygen needed (which is far out of scope of the original question) consider that due to increased depth, PPO will go up, I think the minimal surface PPO is .18, which is 18% oxygen, that will go up with depth. The problem is that CO2 levels (in case of BC breathing will go up as well) which will tell your body that "you are running out of air" which will cause you to breathe more. (this is a reverse of hyperventilating to get rid of CO2 and fool your body into "I dont need to breathe" mode)
.16 is acceptable.... less than .16 and you start running into issues.
I believe if you do 3 breaths, then dump, you won't have too much CO2 to function. But it's just a guess.