Earlier, "Cecil E. Chapman" wrote:

Forgive me if I am asking something that
is a 'given' in your sport, but I assume
by the altitudes you mentioned in your
GREAT account that you carry oxygen with
you?

I can't speak for the pilot in question, but in general sailplane
pilots do carry and use oxygen to at least the minimum degree
specified in 14 CFR 91.211. Where I fly in the Sierra Nevada and in
the Nevada Basin and Range country, most sailplanes are equipped with
oxygen systems. Most such systems are made up of components from
either Mountain High or Nelson:

http://www.mhoxygen.com/

http://www.nelsonoxygen.com/

In my experience, sailplane pilots are far more likely to use oxygen
than most general aviation pilots, and are more knowledgable about its
handling and use.
Personally, I go on oxygen while on the ground whenever I think that
I'll be at or above 10,000 feet MSL during the flight. And that's
pretty much every flight at Air Sailing.

Thanks, and best regards to all

Bob K.
http://www.hpaircraft.com