ScubaOS
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The planner Plus

The maths, done honestly.

Bühlmann ZHL-16C with gradient factors and full trimix, validated against Subsurface on every build. If a plan can’t be dived, it says so and names the limit that broke it.

Get the planner Why “honestly”?

Quick-slate, no-stop planning is free forever. The full deco planner is part of Plus, bought once.

A 45-metre plan: gas, MOD, water, method, cylinder and SAC, with a dive-conduct table of stop-by-stop schedules

The model

The same maths the serious tools run.

Sixteen tissue compartments, nitrogen and helium throughout, gradient factors under your control. Plan a single no-stop dive or a staged technical descent with multiple gases, and read the result like a slate, not a puzzle.

Algorithm
Bühlmann ZHL-16C with gradient factors, full nitrogen + helium. Trimix is first-class, not an afterthought.
Gradient factors
Yours to set. A conservative 30/70 out of the box, tightened or opened as your training dictates.
Gases
Air, nitrox, normoxic and hypoxic trimix; multiple bottom and deco gases with switches at depth.
Outputs
Runtime, first stop, stop-by-stop schedule, total deco, gas use per cylinder, plus longer, deeper and worst-case contingencies on the same slate.
Validation
Every build compares its schedules against Subsurface reference output; the build fails if they diverge.
Determinism
The engine is pure and deterministic: the same plan always produces the same schedule, to the minute.

The honesty

It tells you when a plan won’t work.

A planner that produces a tidy number for an impossible dive is dangerous. ScubaOS refuses to. An unbreathable mix, a missing deco gas, an ascent the model can’t honour: each is surfaced as a labelled error with the limit that broke it.

Warnings are an icon, a label and the offending value, in the same place every time. Never colour alone.

Built to be read by every diver, including the colour-blind
  • ppO₂ and MOD checked for every gas at every depth
  • Impossible schedules raised as errors, never quietly bent
  • At the no-stop limit it offers decompression, not denial
The planner at the no-stop limit: a labelled warning with an icon, explaining the choice: stay within the limit or plan decompression

Recreational ↔ technical

In recreational mode it’s a clean no-stop slate: depth, time and gas in; limit and turn pressure out. Switch to technical and gradient factors, gas switches and the full schedule appear. The same app, revealing depth. Never a different one.

Conditions

Plan the water, not just the gas.

Depth and runtime are half the plan; the other half is what the sea is doing. The trip planner brings tides and currents to the site you’re diving, on the day you’re diving it.

Tides & currents Plus
Tide heights and currents in the trip planner, worldwide.
High-res streams Pro
High-resolution tidal streams around the UK and north-west Europe, where slack water is the dive plan.
Repetitive dives
Plan a whole trip: residual nitrogen carries from one dive to the next, the way your body does it.

Plan your next dive.

Quick-slate planning is free forever. The full decompression planner is part of Plus: £24.99, once, no subscription.

See the plans Next: the log

No software can guarantee a safe dive. ScubaOS is a planning aid for divers trained for the dives they plan: check every schedule against your own training, your agency’s tables and your computer’s planner, and trust your certified dive computer in the water.