Posted by Jason on September 13, 2000 at 18:15:00:
In Reply to: Re: Secondary Air source question posted by MHK on September 13, 2000 at 15:04:43:
I think there is still value in knowing the quantity remaining, esp with the 13s, which
I no longer consider useful. When you go into bailout mode, you're
probably go to ascend to near the surface (< 30ft) quickly, perhaps
too quickly. You'll then want to do a stop at 15 or 20' for
as long as possible to stop the bubbling. I'm inclined to think
I'd want to nearly drain it dry. But much of that might be
lost if you breathe it empty, and then need to do that
last 15' on a single breathe. You might be less likely to do it
in the 30-40 seconds that you should.
Other places where you might want to know time remaining:
-in kelp or boat channels, you might prefer to not surface if you
have a choice. You could motor along at 15'. Knowing your supply
is useful there.
-if you hand off the unit to a buddy or victim and then start
to escort the diver up, you'd prefer to know in advance that
their air is going away.
The button SPG screws directly into the HP port and doesn't
result in an appeciable increase in drag. It is a failure
source, but one that should fail when you turn on the air,
and for the most part, will not drain that quickly at failure.
I think this is a small downside, but that's a value judgement.
Another judgement is how useful that micro display is for the
circumstances I suggested.
I sold my 13ft kit earlier in the year. I didn't see a
justification for it anymore. I do have a 30ft O2 tank
that might see use - but how I'm not sure yet. For now
it has 32% in it, might become a 50/50 tank if that size
is big enough to be meaningful.