Newsgroups: rec.scuba
Subject: Re: Octopus Ergonomics
From: malc@icon.com (Malcolm Weir)
Date: Wed, 8 Apr 1992 20:06:54 GMT
Organization: Sanyo Icon, Irvine, Ca.

In article <1992Apr7.051333.18580@scifi.uucp> njs@scifi.uucp (Nicholas J. Simicich) writes:
>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).

Yes, NASDS is an agency (the agency?) who advocates the left-hand
octopus/"Safe Second".  The rationale is as follows:

Under the NASDS sharing air system, you do NOT want to give up your
primary, so the Buddy-out-of-Air (BOA) must be receive the Assisting
Buddy's (AB's) safe second.  The AB also wants to make sure that the
stress on the BOA is minimized, so the AB wants the safe 2nd to be
rigged so that when the buddy team are face-to-face, the BOA can just
grab the reg. and start breathing.

Now, in the beginning, there were no ambidextrous regulators (like the
Poseidon Nick mentions), so that in order to have the reg. in the proper
exhaust-port-down position during sharing air, the safe 2nd had to come
over the left side.

It was this configuration that prompted Scubapro to produce the A.I.R.II
system, which in turn lead to the MAJOR split between Scubapro and NASDS
(before NASDS & Scubapro were VERY strongly allied).  The alleged problem
was that the AIR II required that the AB give up their primary, which was
totally contrary to NASDS procedures.  As a direct result of the argument,
NASDS has refused to back down on on their "Never Pass your Primary" stance.

On the other hand, there are many NASDS stores who use AIR II's as their
preferred Safe Seconds.  Regardless of everything else, if you use a pony
cylinder, you're going to get redundancy on the main system and also your
totally redundant system.

Personally, I end up having to have both an AIR II and a standard octopus
in order to teach students with either.

>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?

Absolutely, using an inverted "normal" regulator is a pain... it is
wetter, the tee gets in the way, clearing it involves certain tricks,
etc. etc.  Unfortuneatly, I don't set standards for my agency or for
my store, so I can't change the procedure or the equipment I use...

>--
>Nick Simicich - uunet!bywater!scifi!njs - njs@watson.ibm.com
>SSI #AOWI 3958, HSA 318, NAUI #14065

Malc.
NASDS OWIP 2710.