----- Original Message -----
From: "Don Ward" <[log in to unmask]>


>   John Nitrox wrote, in part:
>
> >one way or the other the
> >amount of gas that goes in is going to come out.
>
> I have found this to be universal truism and I have never dived with a
> rebreather.

This is technically incorrect. A certain amount of the gas going in is
metabolised and won't be coming back out. At least through the exhaust
bag....

Mike


>
> /Don
>