Strike wrote:

> As far as I'm aware the only reason that the witches caps on
> yokes include a
> 'spare' O-ring is to create a watertight seal when the regs are rinsed off
> after the dive.  In fact I can't really see the point of carrying spares
> anywhere on your actual diving gear.  Nobody's going to replace
> an O-ring in the water!  (Are they?)  :-)

I've done it twice.  Once on a beach night dive in Juneau.  I didn't
discover the o-ring was leaking until I was in the water doing a bubble
check with my buddy.  It took about 2 minutes to replace the o-ring while
standing in chest deep water.  This saved walking almost a quarter mile back
up the beach and up a long set of steps to my truck.

The other time was at Peacock Springs in Florida.  My buddy Rob discovered a
leaking o-ring when we were already floating in the basin before a cave
dive.  I swapped out the o-ring for him while he was floating there on the
surface still wearing his rig.  This saved the hassle of climbing out of the
gear and hiking back down the muddy trail to the car for a spare.

As far as swapping o-rings underwater.  This is something you might do on a
technical dive if you are using stage bottles that you turn off and on
during the dive and surfacing to fuss with your gear isn't an option.  This
is probably pretty common on big exploration projects like the WKPP where
they have dozens of safety stages in the water for weeks or months at a
time.  And the freshwater in the caves doesn't hurt the regulator.  But on a
recreational dive there doesn't seem to be any point in playing with o-rings
underwater, especially since that means getting sea water into the regulator
and probably means you should pull the first stage apart for cleaning and
rinsing afterwards.

In any event, even if you don't have a spare o-ring, you can often make the
existing one work by pulling it out and turning it over.

-Kent-


>
> I usually keep a selection in a plastic film cannister in a spare
> parts kit.
> At least there, they're not being abraded by salt 'n' sand.  And if I have
> to change one over, then I prefer to do so in topside comfort!  :-)
>
> Strike
>