hey OneThreeSeven I'm just curious what your diving experience is? DO you use mixed gases when you dive?

just for the record with enough lead any one can go all the way to the bottom (he may not come up)but he can reach the bottom.

Onethreeseven, Unfortunatley someone being able to dive to 1000 feet on a rebreather, or any other apparatus for that matter, does not support your claim of being able to go all the way to the bottom. The AVERAGE depth of the ocean is over 10,000 feet and the real bottom is at about 37,000 feet. There is NO gas mixture that has been used that can take humans to that depth and sustain life. (these depths have been reached by humans in submarines, but that is irrelevant to the issue at hand.) The deepest dives preformed under pressure by humans have been in the 2000 foot range and even these are extrememly rare and dangerous. Despite this they in reality only barely scratch the surface of the ocean. Human beings are land based organisms, and while we will continue to push the envelope of our physiological tolerances it is highly unlikely that humans will ever even reach the average depth of the ocean unprotected by one atomosphere submersible of one kind or another. The claim that there are no physiological limitations limiting the depth that humans can venture underwater is not true. There are countless physiological limitations that affect humans EVERY time we enter the water, no matter what the depth.
Best Wishes,
Sean

Limited by Oxygen partial pressure @ 2 atmospheres absolute. Oxygen beyond this pressure in the system becomes toxic and can cause an O2 "hit". If you keep the O2 at a 16 percent minimum in the mix you can go to whatever depth you can decompress from (depends on inert gas in mix, availability of decompression facilities, PTC etc.)

To dive on air past 190' SW is asking to die. Does this answer your question?

Dan Walker

Actually Dan, a mix with 16 %o2 is limited by a depth of 297 fsw. That is calculated using the reccommended maximum ppo2 of 1.6. I personally never exceed a 1.4ppo2 to give myself an extra margin of safety.
Best Wishes
Sean

quote:

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Originally posted by SGHOWE:
Actually Dan, a mix with 16 %o2 is limited by a depth of 297 fsw. That is calculated using the reccommended maximum ppo2 of 1.6. I personally never exceed a 1.4ppo2 to give myself an extra margin of safety.
Best Wishes
Sean

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That is what I've been taught as well. The limiting factor is definately the ppo2. Although the guy instructing me routinely uses 1.5 ppo2. At some point He2 becomes narcotic as well although the number escapes me right now

Such hostility here.. Anyway.. Ask Dr. Jim Bowden.. He might be able to tell you how far a human can go down..

This might help in this topic.
[url=http://en.wikipedia.org/wiki/Deep_diving#Ultra-deep_diving]Wiki[/url]

Thanks for the link, Harry!

Well get out your cridet card and put yur money where you mouth is. will do this dive any time you like in any place you would like me to do it for some nice new gear.