On Monday, November 25, 2002 9:40 PM, Lee Bell wrote:

> > Is that a cautionary tale that you might care to share?  :-)

> At the risk of being told I was as foolish as I know I was, I suppose I
> should.  Maybe somebody else will avoid the discomfort.  It's not like I
> didn't konw better, or hadn't preached better to others.  While it took an
> odd combination of factors to cause a problem, it's still a case of I
should
> have listened to my own good advice.

Thanks for sharing that - and as is usually the case when one is sitting on
the sidelines, let me make a couple of comments.

(snip)

>At home, I have a very
> specific process for testing and marking my gas and have been a pretty
> consistent advocate of the rule that every diver should test his own gas,
> every time.  Of those who opted for nitrox on the liveaboard, I was the
only
> one that had an analyzer, let alone used it, and I did use it.  Membrane
> systems are pretty reliable.  Once they're set up for a particular mix,
they
> tend to provide it consistently.  My buddy and I both have low gas
> consumption.  It's low enough that have to monitor our nitrogen, and
oxygen,
> status pretty carefully, adjusting our depth to stay in a reasonable
comfort
> zone rather than the time of our dives.  We both like to hug the bottom,
so
> we keep a pretty close eye on our depth and nitrogen load.  Even on 32%,
we
> come as close to our limits as we think safe.  We stay out of the
computer's
> caution zone, but not far out of it.  Knowing this, I did what I've done
in
> years past.  I tested the first few fills to confirm the mix and, quit
> worrying about it.  The membrane system didn't fail me, but the human
system
> did.

The membrane systems aren't perfect.  A few years ago - at Dynamite Pass,
close to the Cod Hole - a rebreather diver who had filled his bottle via a
membrane system failed to analyse the gas in the cylinder.  He died.  Later
analysis revealed that his tank contained straight air.

Strangely enough - and wandering slightly off track - it used to be common
place to crack a filled cylinder and sniff the air in order to detect any
obvious impurities.  That's something that seems to have gone by the by.
Similarly, many people seem content to accept the filling station employees
word as to the oxygen percentage in a nitrox fill without ever confirming it
for themselves.

(snip)
> Two dives later, I got the first hint that something was wrong.
> Two days later, I knew what I'd done to myself for sure.
(snip)
> So, once again, I learned that if you're going to be foolish, you have to
be
> tough.

Mate!  I'd say lucky rather than tough!  It sounds like a combination of
factors and one that, with an aggressive(?) diving schedule using nitrox
tables close to the limit, might still have occurred had you been using air.
(One of the reasons that I dive nitrox observing the MOD for the particular
mix but according to the air tables.)

>I think my arm is getting better, but it's a slow enough process
> that I can't be sure.

I suppose it's a bit redundant to suggest that you consult a hyperbaric
physician?

>I didn't and don't have the level of pain normally
> associated with DCS.

Pain is one of the most obvious - but certainly not the only - symptom.  :-)

> Rather I have an relatively constant  ache, just
> enough to remind me of my mistakes.  The numbness seems to be circulation
> related.  It's not constant, but is recurring.  Fortunately, it does not
> seem to occur as often as it did shortly after my incident.

Mate!  I'll say it again:  I suppose it's a bit redundant to suggest that
you consult a hyperbaric physician?  :-))

> The only bright parts of this are:
> 1. When I tested my tank, I tested a friend's tank as well.  His too had
> been filled with air.  His consumption is such that he could not and did
not
> have the nitrogen load I managed to accumulate and he's about 10 years
> younger.  Adjusting his computer for the actual mix was enough for him.
> Lucky him.
> 2. I now have another experience which others can learn from.
>
> Interestingly, I spoke with a now retired commercial diver friend.  His
> question "You screwed up?"  My response "yes."  His question "How old are
> you?"  My response "54."  His statement "That's how old I was the first
time
> I got bent."  Maybe age was a significant factor.

According to Dr Simon Mitchell, past VP of the Underwater hyperbaric
Society, a person's age does not predispose them to getting bent.  He did
say, however, that it often takes longer to effect a cure.

>  Lord knows, I got away
> with doing things that should have bent me like a pretzel when I was
> younger.  The only thing I can say for sure is that if I want to avoid
> additional pain, I'm going to have to be a bit more careful in the future.
> FWIW, I've already decided I'll use nitrox as air on next year's trip . .
.
> AND test my gas before every dive.

Thanks for sharing that experience and I'm glad that it turned out for you
as well as it did - and just to be sure: have you consulted a hyperbaric
physician?  :-)))

Strike