# Time to Surface – Deco Planner — Trimix, nitrox dive calculator > Technical dive planner for staged decompression and gas calculations. (iPhone/iPad app by RUSTAM ISMAILOV.) - Source: https://appshunter.io/ios/app/time-to-surface-deco-planner/id6803187271 (this page in markdown: same URL + `.md`) - Developer: [RUSTAM ISMAILOV](https://appshunter.io/developer/6799582362) - Category: Sports, Utilities - Price: Free - Rating: 5.00/5 from 1 App Store ratings - Age rating: 4+ - Requires: iOS 17.0 · 4 MB - Languages: American English - Released: 2026-09-01 - Data updated: 2026-10-07 - Monetization: free - User reviews in markdown: https://appshunter.io/ios/app/time-to-surface-deco-planner/id6803187271/reviews.md ## What is Time to Surface? Staged decompression from 15 to 51 metres — deeper to 56 with a warning — on six bottom gases, with one deco bottle. Runtime, stops, minimum gas and both cylinder fills, before you kit up. Free. No in-app purchases, no subscription, no account. WHAT IT PLANS • Staged decompression, 15 m to 51 m, and to 56 m with a warning rather than a refusal • Six bottom gases: EAN32, triox 30/30, EAN28, air, 21/35 and 18/45 • One decompression gas — EAN50 or oxygen — in an AL80, AL50 or AL40 • A second deep segment before the ascent, deeper or shallower than the first • Twin cylinders on the back, yours to pick • Bühlmann ZH-L16C, gradient factors yours to set, 20/85 by default • ppO2 1.2 bar working and 1.6 bar at a stop by default — stricter than the 1.4 most divers trained at. Both adjustable • Descent 20 m/min, 9 m/min to the first stop, 3 m/min between stops, and the last 6 m at 1 m/min. Stops every 3 m with the last at 6 m. All four rates adjustable • Metric or imperial THE GAS PLAN Back gas fill and turn pressure on thirds, halves or all usable, every pressure on the ten-bar grid. Minimum gas — what two divers on one back-gas supply need to leave the deepest point and reach the first deco gas at 3 m/min, with a minute for the problem and a minute for the switch. The fill is the bottom phase, descent included, plus that minimum gas. Deco bottle fill and reserve. CNS. The deco bottle is walked level by level from the schedule that was actually solved — every stop, every travel leg and the slow last six metres. And it says which of the three ends the dive — your back gas, your deco bottle or your CNS clock — and at which minute. THE DIVE, MINUTE BY MINUTE Every leg carries the runtime it starts at and the runtime it ends at, so you can see where each line begins and ends without doing arithmetic. One tap lays the whole plan out as a wetnote page — schedule, gas checkpoints and on-the-fly adjustments — sized to copy by hand. DIVES BEFORE THIS ONE Keep a plan under a name, then say that up to three of them came before the one you are planning, each with the surface interval before it. Nitrogen and helium both cross the interval, and CNS decays at a 90-minute half-time. No published table covers repetitive decompression dives; this runs your own previous profiles through the same model. ON-THE-FLY ADJUSTMENTS Five minutes more or less on the bottom, or three metres deeper or shallower — each one re-solved through the same model, not scaled by a rule of thumb, with the change in deco minutes and what it costs in each cylinder. If a change goes past a limit, it says so. PRAGMATIC DECOMPRESSION Off by default. Switched on, it linearises the stops between 21 m and 9 m into one flat time per rung, and the 6 m stop is the longer of those stops added together and what the model needs there — a simpler profile to run in the water, not a more conservative one. The unadjusted profile is what the app computes otherwise. WHAT IT DOES NOT PLAN Closed-circuit rebreathers. Cave or wreck penetration. Hypoxic mixes and travel gas. More than one decompression gas. Altitude — sea level only. It does not compute OTU. One decompression gas per dive is a stated limit of this release, not an oversight. If your plan calls for two bottles, this is not your planner yet. INSIDE ITS ENVELOPE, IT REFUSES RATHER THAN WARNS A gas past its oxygen limit, an exposure past the maximum, cylinders that will not cover the plan, a surface interval under an hour — all produce no numbers at all, rather than a number with a caution attached. YOUR DIVE COMPUTER OWNS THE DIVE This is pre-dive arithmetic. It never pronounces a dive safe, and it is not a substitute for training, for your computer, or for your own judgement in the water. Offline. No ads, no analytics, no tracking. Nothing leaves your phone. iPhone, iOS 17 and later. Questions and bug reports: timetosurface@ismailov.net ## Key features - Staged decompression planning (15-56m) - Support for six bottom gases and one deco gas - Twin cylinder configuration - Bühlmann ZH-L16C model with adjustable gradient factors - Adjustable ppO2 and descent rates - Repetitive dive planning - Contingency scenario calculations ## Frequently asked questions about Time to Surface ### 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. ## Version history (last 5 releases) ### 1.7 — 2026-09-25 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. ### 1.6 — 2026-09-21 The shared picture ends with the App Store link and a QR code for a buddy, beside the app's icon, and the share sheet opens with the picture on the first tap. Every boundary on the runtime ladder, and the total dive duration, round to the nearest minute — a 1.1-minute move prints 1, not 2 — and the swim from 6 m at 1 m/min prints its six minutes. The minimum gas (?) states the rule and its assumption: C × A × T — two divers on one supply, never below 2 × 20 L/min; the mean of the pressures at the level and at the switch; the ascent at 3 m/min plus a minute for the problem and a minute for the switch. More apps by the author, from Settings. ### 1.5 — 2026-09-19 The decompression is cleared at 6 m: the long stop is there, and the slow swim to the surface comes after it. Descent 20 m/min by default. Deco time counts from the gas switch to leaving 6 m. The back gas fill is the bottom phase plus the minimum gas, every pressure on the ten-bar grid, and the wetnote schedule is a three-column table. In pragmatic mode the 6 m stop is at least the 21–9 m stops added together. Bottom time counts from the surface by default, as your team and DecoPlanner count it — untick "Descent inside" to set minutes at max depth instead. Gradient factors per plan: 20/85, 30/70, 40/85 or your own pair, saved with the plan. The runtime ladder reads depth, duration, runtime, says once how a stop is held and where to slow to 3 m/min. The Plan card is four figures under the total dive duration. The gas plan says what you leave the bottom with and switch on, and about how many bar every 5 minutes at depth. On-the-fly adjustments: what +5 or −5 minutes at the bottom, or 3 m deeper or shallower, add in deco and cost in gas — re-planned, not a rule of thumb. View details opens the whole plan on one page, and that page is what you share as a picture. The bottom gas row shows air, 21/35 and 18/45 with the rest behind More gases; a locked time slider says why. Two-level dive profiles. A dive no longer has to be square: add a second level on the Dive card — any depth, any time, shallower or deeper than the first — and the deco is solved for the whole profile. The plan prints both levels, the minimum gas from each, what you leave each level holding, and the turn pressure names the level it falls in. The wetnote carries both rows. ### 1.4 — 2026-09-16 The store listing now says what the app is in the words divers search for. Nothing in the app changed: every schedule, gas figure and limit is what 1.3 printed. ### 1.3 — 2026-09-15 A new look: a photograph at the top, an icon on every section, the runtime and the four legs as tiles, and the plan in three cards — the figures, the profile with the schedule under it, and the gas plan. Share as image sends the whole plan as one picture: runtime, legs, CNS, the profile, the schedule and both fills. Nothing in the planning changed: every schedule, gas figure and limit is what 1.2 printed. ## Apps similar to Time to Surface | App | Rating | Price | Category | | --- | --- | --- | --- | | [Dive Toolbox](https://appshunter.io/ios/app/dive-toolbox/id6759796903) | — | Free | Sports | | [krakentools – TEC/REC Tools](https://appshunter.io/ios/app/krakentools-tecrec-tools/id6761906896) | — | Free | Sports | | [Tech Dive](https://appshunter.io/ios/app/tech-dive/id6483004689) | 5.0 (2) | Free | Sports | | [Abysner](https://appshunter.io/ios/app/abysner/id6636477320) | 5.0 (2) | $2.99 | Sports | | [Below: Scuba Dive Log & Sites](https://appshunter.io/ios/app/below-scuba-dive-log-and-sites/id6756759745) | 5.0 (4) | Free | Sports | | [Dive Kit: Deco Planner & Tools](https://appshunter.io/ios/app/dive-kit-deco-planner-and-tools/id6753089545) | 5.0 (1) | Free | Sports | ## More apps by RUSTAM ISMAILOV - [Four & Six Breathing Exercise](https://appshunter.io/ios/app/four-and-six-breathing-exercise/id6799582360) - [Turn Pressure – Dive Planner](https://appshunter.io/ios/app/turn-pressure-dive-planner/id6801749776) - [Weights Check – Dive Weighting](https://appshunter.io/ios/app/weights-check-dive-weighting/id6806640499) - [Surface Interval – Dive Videos](https://appshunter.io/ios/app/surface-interval-dive-videos/id6813333816) All apps by RUSTAM ISMAILOV: https://appshunter.io/developer/6799582362 --- *Data collected daily from the US App Store and indexed by [AppsHunter](https://appshunter.io/). User reviews are verbatim App Store reviews. Ratings, prices and chart positions refresh continuously; this snapshot is from 2026-10-07.*