Sling a 72

[DaleC]

Mea culpa.

I did actually toy with the idea slinging my old steel 72 (since I rarely use it these days).... but since I had an Al30 and several Al80's I could sling, I never got around to trying it out....

But now I'm moving towards "indy" doubles anyway :scubadive:

Best wishes.

Soon (insert heavy breathing here) you will join me on the darkside (insert heavy breathing here) and together (insert heavy breathing here) we will rule the galaxy (man I gotta quit smokin).

Why would you breathe it down halfway and switch? That's a strategy we use in cave diving, where we are diving thirds. In open water diving, it would be reasonable to breathe the stage down as far as you are comfortable doing, and then switch to backgas, keeping your minimum gas reserve in your backgas tank. Figure the total usable gas, and the appropriate gas management strategy for the dive.

Even though I'm OW diving for the most part I actually manage my twins much like one would when cave diving (not thirds though).
I breath half off one cylinder, switch, and then breath off the other to (at most) half again. At this point (max penetration on a cave dive) I have two independant tanks with adequate reserve levels in each. Then I begin my ascent or move up to a shallower level where new rock bottom values apply. Switch out one cylinder and I can do a second (smaller) dive with a full cylinder and a 30-40cuft reserve.

Half is an arbitrary mark true (depends on the cylinder size as well) but it works for most of my recreational dives (80 - 120') where many carry 30-40cuft ponies as a reserve instead.

I do agree however, that it is important to understand ones actual required reserve gas volumes before using a generic "rule of thumb" so to speak. I've even found that diving twin 80's often leaves me with far more than enough gas on many dives so I've stepped down to twin ST72's.

Triple 40's are only a hop skip and jump away.