Deco Planner
The full model: Buhlmann ZH-L16C with gradient factors. Set the dive and the gases you carry - get the stop schedule, run times, gas switches, CNS clock and gas totals. Works offline on the boat.
| Depth | Stop | Run | Gas |
|---|---|---|---|
| — | |||
Stop times include the travel to the next stop, rounded up — the way dive tables are cut. Descent 14 m/min, ascent 9 m/min, stops every 3 m.
A planning tool, not a dive computer. Dive the plan with a computer on your wrist, cross-check it with your team and your training, and never dive a schedule you have not verified. If this plan and your computer disagree — the longer schedule wins.
The maths, explained
This is the full model, not a shortcut: Bühlmann ZH-L16C with gradient factors — the same family that runs inside Shearwater computers, Subsurface and MultiDeco. Sixteen theoretical tissue compartments load and unload nitrogen and helium (half-times 5–635 min for N2, 1.88–240 min for He); the coefficient tables here are digit-for-digit the ones in Subsurface, and the loading maths is verified against published reference values on every build.
During depth change the tissues follow the Schreiner equation; at constant depth, classic Haldane exponentials. Each compartment tolerates a supersaturation limit (its M-value, Ptol = Pamb/b + a) and gradient factors scale how close to that line you are allowed to get: GF low sets the depth of the first stop, GF high the supersaturation you surface with. The schedule holds each 3 m stop until the leading compartment clears the next stop at its allowed fraction, switching to the richest deco gas whose pO2 permits — EAN50 at 21 m, oxygen at 6 m.
Two honest conventions to know: time at depth here excludes the descent (we add it for you — run times shown include everything), and stop durations fold in the travel to the next stop, rounded up to whole minutes, exactly how tables are cut. Different planners pad differently: at the same stated GF, this engine gives the tightest schedule the model permits, verified minute-by-minute — our house Splash planner pads intermediate stops and lands close to this tool’s GF 30/70 preset, which is why that is the default. When two plans disagree, dive the longer one.
The CNS clock follows the NOAA single-exposure limits and OTUs the standard pulmonary formula. Long oxygen hangs get an air-break reminder automatically.
This Is Exactly What We Teach On Decompression Procedures
A planner shows you the schedule - training teaches you to dive it, carry it, and fix it when the dive stops matching the plan. Staged decompression done properly is exactly what this course is for.
Checked, not trusted: the formulas on this page are pinned by 130 automated reference checks that run on every change — cross-validated against Subsurface’s published planner tests, the independent DecoTengu implementation, printed MOD tables and the team’s own Splash apps.
For training and planning purposes only. Analyse every mix before you breathe it and always dive within your certification.