From: njs@scifi.uucp (Nicholas J. Simicich)
Subject: Re: Octopus Ergonomics
Organization: Nick Simicich, Peekskill, NY
Date: Tue, 7 Apr 1992 05:13:33 GMT

In article <1992Mar31.155837.25325@hubcap.clemson.edu>
mjs@hubcap.clemson.edu (M. J. Saltzman) writes:

>Octopus regulators are available with the hose mounting on the right
>side (looking at the mouthpiece) or the left side.  Usually, you see
>a right-hand-mount unit set up to come over the right shoulder, same
>as the main second stage.  At least one agency (I forget which one)
>apparently advocates having the octopus come over the left shoulder,
>which I assume is the reason for left-hand mounts.

I don't know of any agency that specifically advocates this.  Can
anyone fill this in?  As far as I know, the big controversey is 'pass
the primary' vs. pass the secondary.  Some agencies teach 'Pass the
secondary' (PADI) some teach 'pass the primary' (SSI) and some leave
it up to the instructor (NAUI).  

Agencies or instructors that teach pass the primary typically advocate
octopus mountings which specifically make it easier for the diver to
recover their octopus.  Examples of this style are the Scubapro Air
II, the Tekna second wind, the Sherwood Shadow, and the Zeagle Octo+.

Aother example is that at least one shop I know of that teaches pass
the primary but uses the usual under the right arm octopus position
makes it a point to set up the octopus regulator with the short hose,
and the primary second stage with the long hose.  

And I know of one 'pass the secondary' person who uses a left side
reversed octopus, because it is easier to pass to a student.  He is a
long time instructor.

>On the other hand, I recently saw a left-hand mount unit set up to
>come over the right shoulder.  It seems like this may be better for
>the buddy than the conventional mount, since the mouthpiece faces the
>buddy without having to twist the hose around.  It's a little less
>convenient for the diver wearing it, but how often do you use your own
>octopus?  If you're out of air, it's no help, and most second-stage
>failures are likely to be free-flow failures rather than freeze-ups,
>right?  

Us pass the primary folks believe that your secondary is for you, and
your primary is for your buddy.  So this would be bad.  The pass the
secondary folks should have been trained in a routine which gets
divers into an appropriate position for secondary passing, like
grabbing on to each other's tank valves, or securely grabbing the
other person's BC and drawing them in to you followed by a right arm
clasp.  This routine might be interfered with by a reversed regulator.
As you point out, the reg has to be turned in a different direction.
But people can be single minded about getting the mouthpiece into
their mouth in a case like this, and I suspect that it would matter
little. 

>The other relevant point I can think of is that when attached
>to the BC with an O-ring, if the cover is facing out (so it's easy to
>grab) then the exhaust port is on top, and the reg has to be turned
>over (rather than around) to fit in the buddy's mouth.  (The unit I saw
>had an extra large exhaust port, so you couldn't miss it.)
>
>What do people (especially instructors) think?  Does it make a
>difference?

Solve the whole problem.  Purchase a Poseidon regulator.  The second
stage doesn't have a top or a bottom.

I've done a few dives with a Sherwood Brut on the wrong side, on a
Pony bottle where it really was for me.  On the one occasion I
actually used it, it was sort of inconvenient to have the exahust tee
up.  It caused my mask to flood. Additionally, many regulators are
much wetter when used inverted.  Why add more stress to a more
stressful situation?


-- 
Nick Simicich - uunet!bywater!scifi!njs - njs@watson.ibm.com
SSI #AOWI 3958, HSA 318, NAUI #14065
Join the movement ---  turn 'to bush' into a verb.