[afterburner]

These seem to talk mostly about diving, where you breathe from a regulated air supply. I assume that air supply is not at 30-100x atmospheric pressure?

[bboygravity]

If the air supply wouldn't be at a slightly higher pressure than that, the air would get sucked out of your lungs as far as I understand.

This is why dive tanks run out way way faster the deeper you go (around 1 hour at 18 meters deep and around 10 minutes at 30+ meters out the top of my head).

[heavenlyblue]

Air supply is at that pressure, but they don't breathe the same mix as atmospheric air. Atmospheric air becomes narcotic at 4 atmospheres.

[Grimburger]

The air is at that pressure, as is the surrounding water pressure on the human body.

We are remarkably good at handling higher pressures.