Lift bag gasLift bag gas
Volume of gas needed to lift an object from selected depth.
Before you send up a lift bag, check how much gas it takes. The object's own volume of displaced water already helps, so only the rest has to come from the bag.
How it works
gas = (weight − volume × water density) × (depth ÷ 10 + 1)
- Water density salt 1.03, fresh 1.00 kg/L
- Volume the volume of the object itself
Example
- Object
- 100 kg, 10 L, salt water
- Depth
- 10 m (2 bar)
- Gas
- (100 − 10.3) × 2 = 179.4 L
How it works
gas = (weight ÷ 62.4 − volume × water density) × (depth ÷ 32.8 + 1)
- Water density salt 1.03, fresh 1.00 (relative to fresh water, 62.4 lbs per cf)
- Volume the volume of the object itself, in cf
Example
- Object
- 200 lbs, 1 cf, salt water
- Depth
- 30 ft (1.91 bar)
- Gas
- (200 ÷ 62.4 − 1.03) × 1.91 = 4.16 cf
Take it to the dive site
The same calculator works offline in the Deep Tools app, together with the dive planner, dive log and blender.
