Dear Mike, Peter, Carl and NEDs:


        1)  My error, the Ray has one orifice, the Atlantis I and Dolphin both
have 3.

        2)  Carl's hit this pretty hard, but here it is one more time in yet
another guise.  An Atlantis I 60% orifice delivering 5.8 liters per minute
of gas is the ultimate Kevorkian killing machine when used with air, low %
nitrox, or if the flow valve is clogged or the cylinder is empty or turned
off.  The higher the workload the quicker you go.  Perhaps a flash of
tingling or numbness and you're off to dreamland dancing with the angels.
It's the way I'd like to go, but I'm not in any rush.  Also, note that
there is little hypoxia risk with open circuit and even on the oxygen
toxicity side open circuit is equally forgiving of a bad O2 analysis if you
try to dive to the MOD indicated by the FO2 in the bag and not that in the
bottle.

        3)  You have minimal control over when the unit belches.  You can empty
the exhaust bag and the inhalation bag through your mask when you begin to
approach a fish, but you must move swiftly before the circuit fills and the
exhaust valve blows because, in my experience, fish find close proximity of
the blast quite disturbing.  If the valve is screwed down loosely you have
more blasts with fewer bubbles and vice versa, but one way or the other the
amount of gas that goes in is going to come out.

        That said, if the choice were between open circuit and a semi closed
circuit Draeger, I'd get in line for the Draeger, assuming the prices were
comparable and the Draeger had an Oxygauge.  BTW, did anyone mention "toxic
cocktails", aspirating vomitus, 'sorb depletion and channeling, or
breathing bag rupture?  There, that should shorten the line a little bit.


DPTNST,


John