On Sunday, August 12, 2001 2:16 AM, Huw Porter wrote:

> Over the course of 100 dives around the world, I have dived with, and even
> been on the same boat as, just one diver set up to donate the primary.
> (And that was Strike.)

I'm late coming in to this thread in response to Angelo's question, but I'd
like to add a few points.

The reason that I donate the primary is largely historical.  Before the
introduction of an Alternate Air Source, gas sharing skills relied on
profficiency in buddy breathing skills, (twin-hose and, later, single hose);
an evolution that works well in theory, but one that requires considerable
practice to master.  (There's a tendency for folks to concentrate on the
buddy-breathing procedures and to forget about the need to, at the same
time, ascend!  The reason for many dual fatalities.)

The introduction of a secondary regulator was intended to reduce the task
loading on an OOA diver and allow the donor greater control over managing
the ascent.  Here in Oz, certainly, the OOA diver was taught to take the
primary.  The rationale being that it was seen to be working and that their
focus of attention was reduced to the donor's facial area, (because of the
need to communicate their plight to the 'rescuer', as well as the fact that
bubbles of air were coming from that regulator indicating that it was
functioning!) :-)

It also ensured that - because they were going to be the one that, in a
pinch, would have to breathe from the thing - the back-up regulator was
adequate to the task and well maintained!  :-)

(I've lost track of the number of folks that I've dived with who's back-up
reg was selected for its price alone and that delivered poor gas flow.)  :-)

The way that air-sharing was taught - including dispensing with training in
buddy-breathing techniques - changed when A.I.D.S. became an issue!

Many instructors questioned the wisdom of repetitetivly breathing from their
students primary regulators during training.  The emphasis moved to donating
the secondary regulator.  The problem, however, still remained the
'in-your-face' restrictions of the short hoses.

And, of course, the fact that in 'real-life', the primary was the reg of
choice for a fixated and possibly close-to-panic, OOA diver.

I, for, example switched to a long (5ft) primary hose in '97, when it became
apparent - after two separate OOA incidents with supposedly 'experienced'
divers - that a longer hose would give me greater control over the
situation.  (It proved itself two weeks after I switched!)  :-)

Because - in a teaching capacity - snorkels were required to be worn, I
found it more convenient to pass the hose under my right arm and retain the
excess bight in my waist strap.  A configuration that allowed for easy and
quick passing-off of the regulator should it be required.  (Although I now
wrap the hose in the method that Huw described, I still believe that a
snorkel is an indispensible item of safety equipment for ocean diving and
carry a collapsible one in my back-plate pouch!) :-)

Strike