SAC and RMV
Measure your own gas consumption from a dive you have already done.
The dive
Straight off the computer and the gauge.
Water volume 11.1 L — the internal volume, not the cubic-foot rating.
bar
bar
m
Average, not maximum.
min
RMV
13.2L/min
Yours. Carries between cylinders.
SAC
1.19bar/min
On this cylinder only (AL80).
Gas used
1665L
Surface-equivalent volume.
Pressure at depth
2.80bar
Ambient at 18 m.
Why there are two numbers
Conflating them is the usual gas-planning error.
RMV is how much gas your lungs move per minute at the surface. It is a property of you, so it is the figure worth keeping and the one gas planning asks for. SAC is how fast the needle falls on one particular cylinder — the same diver on a 15 L shows a lower SAC than on an 11 L without breathing any differently.
Dive log
Several dives of the same kind give an average worth planning on. Held for this session only.
| Cylinder | Avg depth (m) | Time (min) | Used (bar) | RMV (L/min) | SAC (bar/min) |
|---|---|---|---|---|---|
| No dives logged yet. Enter a dive above and log it. | |||||