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From: "David Shimell (shimell)" <shimell@se*.co*>
To: Stuart Morrison <divebimbo@li*.fr*.co*.uk*>,
     TechDiver
    
Cc: boubker_badr@ds*.co*
Subject: RE: Help on open water configuration
Date: Tue, 20 Apr 1999 16:24:34 +0100
Stuart

Words fail me for a moment since I do not wish to call you names even though
I would like to.

The stupidity presented in your email below is downright dangerous and stems
from a lack of understanding of Hogarthian configuration and DIR principles.

You present a classic example of someone who is thinks they have made
refinements to a Hogarthian rig but instead have created a whole series of
potential problems.   The proper thing to do would be to post your proposed
improvements for people to consider.  You have not done this but instead,
you offer it as advice in reply to another's post.

What you have done is to select the wrong equipment (thick neoprene dry
suits) that mean that you must then adopt convoluted procedures as you can't
comfortably access your isolator.  You go on to describe who you then have
to convolute the rest of your gear so as to have the SPG on the same side as
the primary breathing hose.  It just goes from bad to worse.

The information you present is a danger to all who adopt it.

Please keep quiet.

David Shimell
Project Manager, Sequent Computer Systems Ltd., Sandton, South Africa.
Email: shimell@se*.co* <mailto:shimell@se*.co*> 

-----Original Message-----
From:	Stuart Morrison [SMTP:divebimbo@li*.fr*.co*.uk*]
Sent:	Monday, April 19, 1999 7:41 PM
To:	TechDiver
Cc:	boubker_badr@ds*.co*
Subject:	Fw: Help on open water configuration


With reference to Kent's rig, I'd agree, nothing much changes from the
normal rig. The one change I make is more with procedure than
configuration. If the water is cold then you can assume that the diver is
using warmer, thicker underclothing than normal. In UK waters a lot of
divers tend towards thick neoprene drysuits. All this can restrict movement
which might make reaching valves harder. Add to this the loss of dexterity
and hand strength that cold brings, and the fact that cold water divers are
at a higher risk of freeflowing regs and it could all end up going horribly
wrong when trying to shut valves down.

My technique is to leave the isolator on the manifold closed, so that I'm
effectively diving with independant tanks. If I have a freeflow, etc., I'm
not under the same pressure to do something about it. If I reach my valves
then great, but if I don't then it's not a problem, I still have half of my
gas safe.

During the dive, I breath off about 30bar (400-500psi), crack open the
isolator, let the tanks equalize, then close it again. I keep doing this
until I reach thirds. I'd rather manipulate the valves when I'm calm and
not under pressure than in a life threatening situation; it reassures me
that I can actually use the manifold and keeps me in practice; and it takes
away one more thing to worry about, especially when diving alone or in
tight caves. If I forget to equalize then all that is going to happen is
that I hit thirds sooner than I would expect to. I can equalize on the fly
without having to stop what I'm doing too.

The downside is: you MUST have the pressure gauge on the side of the
manifold you are actually breathing from. Also, rapid equalising can cause
condensation inside the donor tank but if you are keeping up the oxygen
service rating on your tanks then the annual inspection will catch it.

A couple of other things. I like to use climbing karabiners on my stage
tanks because they are big and easy to use with cold hands. Some electrical
tape can be used to stop them rotating (they can rotate so that the gate
opening is in an unreachable position). Some people say that they are an
entanglment risk because they open and close so easily, but like my cave
instructor once told me, you shouldn't be close enough to get tangled in
the first place. Don't use the locking type, in salt water they can lock up
permanently.

Rather than a knife, I use shears. With thick gloves they are easier to use
if you get the small, spring loaded gardening type than a knife is. They
will also cut through a hell of a lot more stuff. Plus they are dirt cheap.

Final thing, watch what kind of hoses you get, because some can become very
stiff in cold climates.

Regards,

Stuart.
----------
> From: boubker_badr@ds*.co*
> To: techdiver@aquanaut.com
> Subject: Help on open water configuration
> Date: Friday, April 16, 1999 9:24 AM
> 
> 
> Hello all,
> I am new to this list.
> I dive mainlly in cold water (wet suit) and in tropical water with a
single
> tank.
> 
> I am new to the Hogarthian principle, but I like it very much.
> 
> Can some one email me a good Hogarthian configuration for "cold water
open
> water diving" (that they have tested of course)?
> The only information I have found on the web is for "cave diving".
> 
> Thanks for the help and sorry if its not the right list to ask for ;-)
> 
> Boubker.
> 
> 
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