Mike Wallace wrote:

> O2 and dilutent can be the same thing. Let's just call it supply gas. The
supply gas
> could be used as a bailout depending on the breather and what the gas is
of course.

O2 and dilutent, in my mind can't be the same thing because they're in
separate tanks.  We can call them supply gas, but if they are, in fact, in
two separate tanks, it won't help me understand.  Are we saying that the
only gas that was added to the counterlung was nitrox and that the O2 was
there strictly as open circuit deco gas?  If so, I understand your
statements, but not the rebreather itself.  I thought that the mix was
adjusted by adding both O2 and some dilutant gas.  Was I wrong?

> You are using a portion of the O2 in the loop with each breath. This used
O2 must be
> replaced or you will eventually use all the O2 in the loop. In the Dolphin
breather, the
> supply gas is Nitrox. Once the supply bottle is empty, if you continue to
breathe the
> loop gas you will eventually use the O2 to a point that it will not
sustain life.

So the O2 bottle was not part of the rebreather system at all, correct?  I
guess I'm being confused by my limited study of closed circuit rebreathers.
In fact, just before I wrote the previous questions, I did some quick
research into the term dilutant, which took me to a Draeger Dolphin that had
been converted to closed circuit.  I thought it informative.  Now I suspect
I simply confused myself.

Here's the website if you're interested.
http://www.therebreathersite.nl/evolution_of_a_rebreather.htm

Lee