Sutty

Cedric, I understand that you are trying to keep it simple. My concern is that over-zealous "punching out" of gas may drown a victim who might have made it otherwise. How about only expelling gas if there isn't significant bubbling from mouth or mask on ascent (if there is then victims airway is at least partially open), if little/no bubbling then expel gas each time you have to dump air from your wing - keeps it easy and matches the physical volume changes.

Mike, unless there is something special about O2 convulsions compared to "ordinary" seizures I can't see why the victim would not re-start breathing (may be a pause), or at least attempting to. Whether they can breathe depends on whether the airway is open of course, and whether they have anything to breathe from.

One advantage of some FFMs could be that the victim could breathe through the nose, the nasal airway is easier to keep open than the oral one (ironically the oral airway may be easier to keep open if some form of mouthpiece is in the mouth). This is also why I would not remove a mask to hold the nose closed, you'll have to let go at some point and there's not too much water in a mask.

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