Huw Porter wrote:

> An increasing number of divers (but not, by a long, long way, even close
to
> a majority!) have started to adopt a different configuration, where the
reg
> in the mouth is donated to a diver with a problem.

It would be interesting to count, but hard to get a fair one.  Most forums
tend to contain a higher number of people on the edge of technical diving
than the general population (interest factor) and that's one of the major
sources of change.

> In order to do this, the 'primary' second stage is on a considerably
longer
> hose than an octopus, between 1.5 - 2 metres long.  The hose comes from
> your first stage, under your right arm, round over your left shoulder,
> behind the neck and into the mouth from the usual side.  The 'backup'
> second stage is worn hung on a necklace on a short hose which comes over
> the right shoulder.  After donating the 'primary' to an OOA diver, you
> switch to your backup.

This is the DIR setup and what I use.  I know it sounds more complicated and
like it's more of an entanglement hazard than a more conventional setup, but
it's not.  You kind of have to see it to understand.  This setup is,
however, only one of two that result in donating the primary.  The other,
the combination alternate/inflator is, in my observation, far more common
and much more significant to the trend I perceive.  Between the two, there
may be a majority already and probably will be eventually.

> It is still pretty unusual (except possibly in Florida ;-)

Florida because it is the most popular cave diving destination in the U.S.
(pretty much for sure) and maybe in the world (yes, no?).  It is also the
home of the WKPP who devised the DIR systrem and where I live (very small
impact on reality, potentially large impact on my bias.

> It is said to be possible to get the hose wrapped tight round your neck in
> an emergency.  Many people who use it say this doesn't happen in practice.

In my opinion after using the system for a hundred or so dives and that of
the developers of this system. who I correspond with regularly, it's no more
likely with the long hose than with a standard one and, if this should
happen, is easier to handle with the extra hose than it is with a shorter
one (turning to the left unwinds the long hose and gives the doner room to
deal with whatever situation led to the problem.

> Personally, after doing some pool practice with a buddy with the rules
that
> we could knock each others masks off and/or yank regs out of each others
>mouths at any point, I was convinced of the advantages!

Me too.  As far as I know, a lot of people are converting to the DIR
configuration (and some are even adopting parts of the philosophy).  FWIW, I
don't think I've ever heard of someone who converted back.

Lee