Answer: In the studies I did, my test subjects pre-breathed 100% oxygen at
ground level for a full hour before going to altitude. They kept breathing
100% oxygen the whole time they were there (at 25, 30 or 40 thousand feet)
and they STILL got DCS.

Interesting...what were your "victims" equivalent ascent rates?

As an aside...there is a cave diving group....the WKPP (also known a GUE and
DIR) ...they do extreme duration/depth/penetration cave dives...and get "away
with it" on a continual basis (ie its not a one time stunt where they got
lucky).....we are talking a constant depth of 300 feet for 6 to 8 hours or
more.....and yet they still manage to start such dives in the morning and be
back on the surface totally decompressed by the end of daylight....and doppler
studies even show few/low bubbles...that group has worked out some interesting
deco theory that seems to really work well....so much so the Navy has even been
working with them to learn a few things...if your interesting in it I can
direct you to the right discussion groups....

take care

Blll