Gas planning
How long the gas lasts, when to turn, and what must be left in the cylinder.
The dive
Depth, cylinder and how you breathe.
L/min
Surface consumption, not tied to a cylinder.
m
Water volume 11.1 L.
bar
Holds about 2220 L at the surface.
Reserve strategy
How much of the fill you are willing to spend.
Bottom time
21min
At 30 m, travel deducted.
Turn pressure
67bar
Set by the reserve rule.
Minimum gas
67bar
Two divers up from depth.
Runtime
26min
Descent, bottom and ascent.
Usable gas
1480L
67% of the fill.
Travel gas
181L
Descent and ascent, at mean depth.
Min gas volume
740L
Must remain in the cylinder.
Rate at depth
60.0L/min
15.0 L/min × ambient.
Where the gas goesA 200 bar fill in a AL80, spent.
| Phase | Detail | L | bar |
|---|---|---|---|
| In the cylinder | Full fill, surface-equivalent | 2220 | 200 |
| Held in reserve | 33% by the rule | 740 | 67 |
| Descent | 1.5 min at 20 m/min | 91 | 8 |
| At depth | 21 min at 30 m | 1299 | 117 |
| Ascent | 3.3 min at 9 m/min | 91 | 8 |
| Minimum gas | Two divers, stressed, from depth | 740 | 67 |
Descent and ascent are charged at the mean transit depth, not at maximum depth. Charging travel gas at full depth — as the previous calculator did — overstates it by around two thirds on a deep dive.