Time to Surface – Deco Planner
Trimix, nitrox dive calculator
About
This technical dive planner calculates staged decompression for dives up to 56 meters. It supports multiple bottom gases and one deco bottle, offering detailed gas planning, runtime tracking, and contingency solutions. The app also accounts for repetitive dives and provides a printable wetnote layout.
What's New in Time to Surface
1.7
September 25, 2026
Every (?) behind a calculated figure now shows its formula: what goes in, where each value comes from, and how it is rounded. SCR, surface consumption rate, replaces SAC throughout, and the second level is now the second deep segment. A second deep segment is offered only at depths the plan can use: the depth track runs between them, and a pick lands on the nearest one that plans. CNS: a bottom minute above 1.2 bar counts at its table row where that is stricter, and each deep segment at its own ppO2. At large text sizes, each (?) opens as a sheet you can scroll.
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FAQ
What is the maximum depth Time to Surface can plan for?
Time to Surface can plan staged decompression for dives from 15 meters up to 51 meters. For depths deeper than 51 meters, up to 56 meters, it will plan and warn rather than refuse, as gas density becomes a limiting factor before oxygen toxicity at these depths.
What types of gases does Time to Surface support?
The app supports six different bottom gases, including EAN32, triox 30/30, EAN28, air, 21/35, and 18/45. It also accommodates one decompression gas, either EAN50 or oxygen, in various cylinder sizes (AL80, AL50, or AL40).
Can Time to Surface plan for repetitive dives?
Yes, Time to Surface can plan for repetitive dives. You can save previous dive plans and input the surface interval before the current dive. The app then calculates the impact of nitrogen and helium crossover and CNS decay on your decompression profile.
Does Time to Surface offer contingency planning?
Yes, the app provides contingency planning. It can recalculate dive plans if you lose your deco bottle, add five minutes to your bottom time, or go three meters deeper. If your planned cylinders cannot support a contingency, the app will indicate this.
What dive model does Time to Surface use?
Time to Surface uses the Bühlmann ZH-L16C model. Users can adjust the gradient factors, with a default setting of 20/85. The app also allows for adjustable ppO2 limits and descent rates for customized planning.
How does Time to Surface handle the last part of the dive?
The app plans the final 6 meters of ascent at a rate of 1 meter per minute. It also offers an optional 'Pragmatic Decompression' mode that linearizes stops between 21m and 9m for a simpler in-water profile, though the unadjusted profile is generally more conservative.
Is Time to Surface available on multiple devices?
Based on the provided data, Time to Surface is currently supported on iPhones. Information regarding Android or other platform availability is not specified.
How often is Time to Surface updated?
The latest version of Time to Surface is 1.5, which was last updated on September 19, 2026. The release date for this version was September 1, 2026, indicating relatively frequent updates.
