Rainer
Contributor
Lost deco, bad SAC day....current, stress, ect....
I try to plan that even with current, stress, "bad SAC day", etc that I'd still have enough gas to cover lost deco. Best way to get a sense of this is to be conservative with your planned bottle time after class. Plan for 20 minutes only and see how you do. Then up to 25 and see if that works. I really don't think 30 minutes on a single AL40 is reasonable for most in moderately challenging conditions (cold water, currents, mid-water, etc) if you hope to reserve enough gas to cover a lost bottle. Doing 2x deco on back gas is not exactly fun or efficient.