Posted by Steve on March 27, 2001 at 00:14:10:
In Reply to: trimix or nitrox? posted by mdfixitman on March 23, 2001 at 07:31:40:
The most important ingredient of course is the oxygen which the brain needs to stay alive and managing the partial pressure of O2 is critical in diving whether you dive air, nitrox, helox, or trimix. Technical divers play with different blends to maximize there bottom time and shorten decompression time. In nitrox training you are taught to keep ppo2 to less than 1.4 which for 32%O2 AND 68%N2 is 110' deep. Dive deeper than this and you risk a O2 convultion and drowning. Diving air you reach 1.4 ppo2 at 178' divers go deeper than this we know but it is more risky and throwing in narcosis compounds the problems. The extreme divers have been to 400+ on air but many have died attempting the record. Hypoxic helium trimix is becoming more popular than diving deep air but at the surface and very shallow a 10-12% O2 mix can cause you to pass out. I hope this helps some.
Steve