Nihon_Ni
Well-Known Member
Scuba shops generally use ambient air, not oxygen. If you go deep enough you have to use nitrox so you don't get too much nitrogen. (I'm just an open water diver, so I might be off a little on my explanation.) Unless you had a pressure delivery system, I don't see the value in breathing air from a scuba shop at altitude, since all you're doing is bringing along your own ambient air.