On Wednesday, February 28, 2001 2:42 PM, Wade G. Pemberton wrote:

> The question I was heading Lee toward was:
> After you reach total desaturation, how much additional safety margin do
you get for
> sitting out more hours?

G'Day, Wade!  Sorry to have butted in there, but you've posed an excellent
question, one that's probably best answered by somebody like Doc Lance, but
to which - I believe! - the short answer would be:  Nobody knows for sure!
:-)

It seems to me that, in part, much will depend on the intensity and profiles
of the diving over the preceeding days as well as the algorithm of the
computer - something that fails to consider individual physiology.  (One of
the reasons that, say, liveaboard divers carrying out multiple dives over a
period of days are advised to modify their profiles, or even take a rest
from diving, every three days or so in order for the body to play
"catch-up" - despite what the computer says!  It is, after all, only a
tool - not a talisman!)  :-)

Just to state the obvious as regards to flying after diving:  Passengers in
the cabin of a commercial aircraft are not only subjected to reduced
pressure and a reduced amount of oxygen in the breathing gas, but also to
reduced humidity that thickens the blood.  As the DAN guidelines state:
"Remember:  There can never be a flying-after-diving rule guaranteed to
prevent decompression sickness, no matter how long the surface interval."

It may not have any proven scientific validity, but generally speaking it's
probably true that 'later is better than sooner' when it comes to flying
after diving.  In that regard, it seems to me, Lee's decision to allow at
least 24 hours gap between diving and flying *may* not be necessary - but
there's nothing wrong with erring on the side of safety!  :-)

Strike