Mike,

> > > > I understand things from Draeger's literature and through speaking
> with
> > > > their representatives and Dolphin users, there are still a few
> negatives.
> > >
> > > There are negatives with EVERY rebreather out there.

There are ways to cause problems, just as there are ways to cause
problems with open circuit.  A loose mouthpiece, a stuck pressure gauge.

> > Ok, give me the negatives that are life threatening on the Halcyon.
>
> It's a rebreather.

That is *not* a sufficient answer and I suspect you KNOW that it's not.
Just say "I don't know of any".

> Seriously, I don't know what they are. I have not spent a lot of time
> studying the Halcyon because it's not likely that I'll win the lottery and
> be able to afford one anytime in the very near future. I have no doubt that
> it is considerably safer to dive than the Dolphin, but I also have no doubt
> that there are ways to kill yourself just as dead with one.

WHAT!!!  UNACCEPTABLE.  If you have NO DOUBT then you must KNOW of AT
LEAST
one way to do this, yet, you freely admit that you do NOT know the
Halcyon
and therefore are unable to say anything about it.

Sorry for hammering you on this Mike, but either you KNOW something or
you DO NOT.  You cannot say "I don't know about it BUT I DO KNOW that
it has death modes similar to others".

> > > You are betting your life on your O2 analyzer for any gas dive, be it
> open
> > > or closed circuit.
> >
> > What?!  If I do an OC gas dive the O2 analyzer is *NOT* used in a life
> > support manner.
>
> It most certainly is if you analyze your gas prior to your dive, and I know
> that you do that. You are betting your life on that analyser and the O2 cell
> in it.

No.  You have it absolutely, 100% wrong.  My *primary* way of setting up
that
O2 is by determining HOW MUCH PRESSURE O2 I must add to that bottle,
then
decanting it, checking the pressure gauge (which I have been watching go
up).
I then put in the He (if it's a mix dive - watching the pressure there
up to
my predetermined limit), and top off with air to my predetermined limit.

At that point I *KNOW* what gas is in there.  My O2 measuring system is
used
ONLY as a backup.  If you doubt what I say here I suggest you go say/ask
the same question/statment over on cavers or quest and see what response
you get.

> >I *mix* the gas and I already *KNOW* what percentage
> > the O2 is.
>
> You *KNOW* what % it is if you didn't fuck up the blend.

You are correct.  The point is that I will ONLY get a bad mix *IF AND
ONLY
IF* 6 things happen (5 things for a nitrox dive).

1) I screw up the mix and
2) the O2 gauge is off.
3) That O2 gauge is reading *exactly* what I expected after I pump Pure
O2.
4) That O2 gauge is reading *exactly* what I expected after I pump He
   (this one is ONLY for a mix dive).
5) That O2 gauge is reading *exactly* what I expected after I pump Air.
6) That O2 gauge reads 0 (close to it) when I seal off the chamber with
the
   O2 cell in it.  YOu can see the O2 percentage declining - a smaller
chamber
   will cause it to go down faster.

Normally the analyzer is stored with the analyzer cell sealed.  When you
turn
it on you can take the "0" measurement.  Open up to air to do 20.9%
measurement.  Check out on 100% O2 to check that.  Those are 3 points
that you
*KNOW*.  Tell me, what are the chances of a failed unit working on those
3 points?

Oh, I forgot to tell you, I can test the O2 percentage THREE TIMES when
making
mix.  First after the O2 is pumped (just to make sure I'm measuring 100%
O2
and that the analyzer can see it!).  The second one is after the He is
pumped
and finally after the Air is pumped.

Do you know the failure modes of O2 measuring systems?  Can you tell me
just how many of them would have the O2 gauge be faulty, but, read
exactly
what I expectn in 2 (or 3) of the measurement steps above and what the
PROBABILITY
of that happening is?

Personally I cannot even conjure up a failure mode that would have the
meter
working under the initial conditions I set forth yet still read the
correct
values later, can you???

Come on Mike, simply admit you are wrong here.

> > That O2 analyzer is only used to *confirm* what I already
> > know.
>
> Again betting your life on the fact that you didn't fuck up the mix and that
> the analyser is correct.

See the analysis above.  You will see that your simplistic statment just
doesn't "hold water".

> > Yep, most serious rebreather divers take along bottles of O2 and He with
> > them, or, have them shipped ahead of time.  This isn't a "cheap" way of
> > diving.
>
> Duh... :-)

You *missed* the point.  If someone can *afford* to ship He ahead of
time/etc
then the diving they are doing isn't cheap.  If you can't afford a
proper
rebreather (Halcyon) then you simply shouldn't be diving a POS
(Atlantis/Dolphin).

I guess it all comes down to how much value you put on your own life.  I
figure
that mine is worth at least the price of a Halcyon so if and when I
decide
to dive rebreathes I'll get a proper unit, not a toy.

> > Ok, I'll add the shower in too and the shallow end of the pool.
>
> You da man. I knew I'd get you to cave and admit that it some use other than
> the tub..... :-)

Not with THAT POS you won't!!!

Carl