Posted by Bill Reals on July 08, 2003 at 15:00:59:
In Reply to: Xeno gas posted by Karl S. on July 06, 2003 at 15:28:09:
This has been discussed before. Heli-air is poor-man's trimix, and let's get this straight it still has the 3 components of Trimix, Nitrogen, Oxygen and Helium, so it's trimix.
Also, diving deeper than 100 feet on air is really dumb as your loading your tissues with nitrogen and your hammered out of your mind.
Breathing high partial pressures of Nitrogen is dangerous and hard on the body, so why do it? Replacing nitrogen with helium is a reasonable thing to do for single tank dives as shallow as 100'. What helium does for the 140-170 foot range (previously "deep air") is nothing short of miraculous. You remember the dive, you perform well under stress and you feel better after the dive.
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