Plan the decompression
Depth, time, gases and gradient factors in; stops, runtime, CNS and a gas budget out — recalculated as you type, with contingencies for the dive that does not go to plan.
Bühlmann ZH-L16C · Gradient factors
A decompression planner that shows its working.
Plan open-circuit, closed-circuit and semi-closed dives on a model built from published coefficients. Fly them in real time and watch the tissues load. Then load the log from your own dive computer and see what the same model makes of the dive you really did.
- OC · CCR · SCR
- Every number unit-tested
- Works with no signal
Decompression plannerLive
Runtime
0:37h:mm
Max depth
30m
Deco
7min
Ascent
0:12h:mm
Stops
| 9 m | 1 min | 0:30 |
| 6 m | 2 min | 0:32 |
| 3 m | 4 min | 0:37 |
Tissues
What’s inside
Everything between the plan and the logbook
One model, used the same way everywhere: to plan the dive, to fly it, and to check the one you came back from.
Fly it in real time
Run the dive live or up to 60× faster on auto depth or by hand on buoyancy. Inject a free-flow or a runaway loop and practise the bad day before it happens.
New
Analyse a real dive
Import Subsurface, UDDF, Garmin FIT, Suunto or CSV logs and get findings pinned to the moment they happened: ceiling violations, fast ascents, surfacing GF.
Rebreathers modelled properly
A closed loop stays on the loop; bailout is a decision you make, not one the planner makes for you. A semi-closed loop runs leaner than its supply gas.
The gas plan too
Rock bottom and turn pressures, partial-pressure blending, best mix for a depth and narcosis budget, and gas density flagged against the 5.2 g/L guidance.
No signal required
The model is pure and dependency-free, so the same planner runs in an offline Android build — on a boat, with no bars, forever.
Analyse a real dive
A second opinion on the dive you actually did
Load the log from your dive computer and DiveSim replays it through the same Bühlmann model the planner uses — ceiling, supersaturation and ppO₂ over time, with each finding pinned to the moment it happened.
Subsurface XMLUDDFGarmin FITSuunto JSONCSV
The file is read on your device and stays there unless you save the dive to your logbook.
Premantura cave entrance
UDDF · Shearwater Petrel 3 · 30 m · 32 min
- CriticalAbove the ceiling on the way up
Up to 2.7 m shallower than this model allowed, from 31:40.
- WarningFast ascent: 18 m/min
From 24 m to the surface, peaking around 21 m. The usual limit there is 10 m/min.
- InfoSAC 17.9 L/min
From 200 to 18 bar on a 12 L cylinder. Use it as your planning SAC.
A model you can audit
Computed, not copied from a table
Coefficients transcribed from two independent published sources that agree digit for digit. Schreiner integration for travel segments. Alveolar water vapour subtracted wherever inert gas is taken up.
These no-stop limits come from the model by bisection. Every one is asserted in the test suite, so a change to the engine that moves them fails the build.
18212 m
9015 m
6018 m
4121 m
2924 m
2227 m
1730 m
1136 m
940 m
Plan the next one properly.
Free, runs in your browser, and there is an offline Android build for the boat.