At 10:07 AM 2/16/01 +1100, Strike wrote:
>>
>What's the difference between a 'K' and a 'J' valve?  And where did the
>terms come from? :-)
>
        Thanks for the excellent bibliography, Strike, and I hope everyone took
notes so as to fill the holes in his or her diving education.  As to the
quiz, I may be having a senior moment, but I don't think that the names 'J'
and 'K' have anything to do with shapes as is popularly thought but rather
with their placement in the catalogue; the 'J' valve preceding the 'K'
valve.

        Here's a scary thought for everyone, once they've taken down Strike's
bibliography.  In the U.S. before the big agencies when Los Angeles County
was doing most of the certifying, people would dive with unbalanced regs,
no spg, and a 'K' valve and would start their ascents when it got hard to
breathe.  There were no bcs and no safety stops although people of an
intellectual bent might own a set of Navy decompression tables.  Hmmm,
let's see here, according to these U.S. Navy extreme exposure tables, a
three hour dive at 300' requires 1168 minutes of ascent time.  Now what was
our PO2 on air at 300' and how many OTUs did we get in three hours?  Hmmm,
it's small wonder that these old geezers had more accidents than we do now.
 No doubt the cautious ones stuck to the U.S. Navy Standard Decompression
Tables and came up from 300' feet after only an hour.


DPTSNT,


John