John Chluski wrote:
> 
> Some ocean divers open the isolator only 1/2 to 2 turns to facilitate the
> shutdown.  I have started using this method when diving as other Cambrian
> Foundation team members use this method.  The downside to this method that I


John, thank you for warning us, diplomatically, about the Cambrian
Foundation.  It seems that their organization is appropriately named. 
After hearing this sorry tale the name should be changed to
Pre-Cambrian.  The fact that these folks even consider something as
idiotic as this practice is beyond the pale.  As JJ CORRECTLY taught you
the isolator valve is ALWAYS FULLY OPEN.  

It is very disconcerting to learn that such criminal stupidity still
exists as a formal institutional practice.  When I saw the video of the
Belize Blue Hole exploration at the NACD workshop I overlooked the
displays of hose stuffing, helmet wearing, butt mounting personal
personal preference out of respect for Terry Tysall.    We are aware
that such retrograde practices still exist on the periphery of socalled
"technical" diving, but there becomes a point where you  have to "Just
Say No".  

I might add that George Irvine's response, when learning of this
nonsense, was  unprintable.   As you are well aware, valve closure
during a dive is a very dangerous event which can lead to or seriously
compound an ongoing CF.  Unwitting closure of the isolator manifold
valve can lead to subsequent fatal errors.  If this weren't bad enough,
leaving the valve in a near closed state can cause the valve to become
easily turned off when the tanks are lifted in and/or out of a fill
bath. Just imagine what horrifying scenarios this can cause while gas
mixing.   Let me suggest one to you.

You fill your doubles with 1800 psi of helium for a 50% mix.  While
lifting the tanks you inadvertently shut off the isolator. You then add
the oxygen to your left post (the post which supplies your backup) and
fill, analyze and do the squeaky voice test off of your backup from the
left post.  Your spg shows the correct pressure and you are confident
that the gas mix is ok.  Since you are breathing your long hose, which
is powered off the right post, what happens when you go to  breath your
bottom gas?

Best Regards (or bon voyage),

Bill Mee     


> know of is that it may be possible to close it in the wrong direction if you
> are in a panic.  I am uncertain whether the WKPP uses this method and
> frankly I am only a junior team member based on my skill and experience
> level in deep caves.  I learned from JJ (my full cave instructor) to keep
> the isolator completely open.
> 
> I learned a very good drill last week from Billy Deans (EPIRBs and Bondage
> wings notwithstanding) that he calls the fire drill.  While sitting in your
> gear out of the water have your buddy randomly pick different pieces of your
> equipment one at a time simulating a failure.  You then run through the
> appropriate shutdown procedure to solve the problem.  Your buddy picks
> everything from 2nd stages, spgs, bcd, tank O-rings, 1st stages, etc. and
> see how quickly and comfortable you are at determining the cause and then
> completing the appropriate steps to isolate the problem.
> 
> Keeping the isolator completely closed is much like diving independents.
> 'nuff said on that...
> 
> Regards, John
> 
> -----Original Message-----
> From: Peter Fjelsten +ADw-tek-dk+AEA-usa.net+AD4-
> To: Ken Sallot +ADw-ken+AEA-condor.circa.ufl.edu+AD4-
> Cc: Cavers List +ADw-cavers+AEA-www.geek.com+AD4AOw- Techdiver List
> +ADw-techdiver+AEA-aquanaut.com+AD4-
> Date: Friday, March 27, 1998 7:15 AM
> Subject: Re: seeking opinions on isolator valves
> 
> +AD4-Ken,
> +AD4-
> +AD4-What about diving with the isolator shut - that would give you time to
shut
> down the
> +AD4-malfunctioning regulator but still ALWAYS have approx half of your gas
left
> should you be
> +AD4-too slow. You have to switch regs continuously, though, which may be too
> much task
> +AD4-loading.
> +AD4-
> +AD4-For the record: I dive manifold with OPEN isolator.
> +AD4-
> +AD4---
> +AD4-Undervandshilsener (Sub-Aquatic Regards),
> +AD4-
> +AD4-Peter Fjelsten
> +AD4-
> +AD4-Glanshatten 32C, 5220 Odense S+ANg-, Denmark, +45661568-
> +AD4-------------------------------------------------------------------
> +AD4-Peter Fjelstens TekDykningsWeb: http://www.cdcdyk.dk/pf
> +AD4-------------------------------------------------------------------
> +AD4-Technical Diving in Denmark: http://www.cdcdyk.dk/pf/techdk.htm
> +AD4-
> +AD4-
> +AD4-
> +AD4-
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