At 03:00 PM 4/17/2004, Sr. Feeeesh wrote:


> >It was comforting to know that
> >every case of the bends doesn't leave one paralyzed,
>
>That's common usage (in English) that is accepted.  But logically
>the sentence construction is wrong -- because if EVERY CASE DOESN'T,
>that implies NO CASE DOES.  :-)   Thus, in this particular case, to
>leave no room for ambituity whatsoever, the correct statement is
>
>"NOT every case of the bends leave one paralyzed".

         Dr. Feeeesh is right and while my abuse of the English language
may have come into common usage, it shouldn't have, and I'll try to make
sure it doesn't pass my lips or fingers again.

         Regarding the computer question at issue between Giovanni and
Christian, while I suspect that computers can estimate how long the gas in
a tank will last by measuring changes in pressure with respect to depth
over time, in the case of the Suunto Cobra the time estimate should be
taken with an ocean of salt because the computer seems to make its estimate
for the depth at which the diver consults it.  Perhaps the computer's
estimate would be good if one were planning to stay and die at that depth,
but since most divers ascend, the estimate grossly underestimates how long
the gas will last because it doesn't take into consideration the smaller
amounts of gas breathed at the reduced pressures upon ascent.  To my mind,
the pressure figure is much more valuable than the computer's estimate of
remaining breathing time.  In this month's <Dive Training> there is an
article called, "Does This Make Sense?: Teaching the Sanity Check."  Since
diving is an activity which places the participants at some risk a sanity
check which includes one's computers and their calculations (including gas
time, no deco time, and deco time) seems to me to be a good idea.


DPTNST,


John