Guy Alcala
Contributor
As a relatively new diver, my SAC rate is all over the place. I don't have the equipment to see it instantly, but I calculate it for the whole dive when I can. I've calculated anything from .5 to 2.5, but typically it runs .7-.9 unless I get uncomfortable for some reason. I make up for the poor SAC rate by diving HP130s.
That's more than enough to get there and back. For incremental RMV/SAC rates, I note my depth, time and PSI at various obvious waypoints throughout the dive on my wrist slate, then average the depth if I'm swimming between points of varying depths, or use a constant depth if I'm just idling around a single point (like the barge), calculating SAC and RMV for each increment. This is very useful to find out what your resting, idling, easy, moderate and heavy work rate SACs are as well as the effect of visibility, gear, buddies/solo etc. For the overall dive it helps if your computer does average depths, because using max. depth for your calculation will understate your SAC/RMV.
Guy
