Time to Surface vs Decompression Engine

Staged decompression from 15 to 51 m (56 with a warning), on six bottom gases with one deco bottle. Runtime, stops, minimum gas and both cylinder fills, before you kit up — then your team signs it. Planning is free, with no account and no limit. WHAT IT PLANS • Six bottom gases: EAN32, triox 30/30, EAN28, air, 21/35 and 18/45, in a twinset of your choice • One decompression gas — EAN50 or oxygen — in an AL80, AL50 or AL40 • EAN50 at 21 m even when the first stop is shallower, on by default • A swim to the drop-off before the deep segments, on back gas or the deco bottle • A second deep segment, deeper or shallower than the first • Bühlmann ZH-L16C, gradient factors set per plan, 20/85 by default • ppO2 1.2 bar working by default, set per plan; 1.6 at a stop — stricter than the usual 1.4 • Descent 20 m/min; ascent 9 m/min to the first stop, 6 between stops, 1 over the last 6 m, all adjustable. Stops every 3 m, the last at 6 m • Metric or imperial THE GAS PLAN Back-gas fill and turn pressure on thirds, halves or all usable, on the ten-bar grid. Minimum gas: two divers sharing back gas to the first deco gas at 3 m/min. Fill: bottom phase with descent, plus minimum gas. Deco bottle fill and reserve from the solved schedule. CNS. If gas or CNS cannot carry the bottom time asked for, it plans the longest that fits and names the limit. THE DIVE, MINUTE BY MINUTE Each leg shows the runtime it starts and ends at. A wetnote page — schedule, gas checkpoints, on-the-fly adjustments — to copy by hand. On the fly: 5 minutes more or less, 3 m deeper or shallower, each re-solved, with the change in deco minutes and gas per cylinder. PRAGMATIC DECOMPRESSION Off by default, chosen per plan. On, each 21–9 m stop gets one time, and the 6 m stop is the longer of their sum and what the model needs: simpler to run, not more conservative. BRIEFS AND DIVE SITES A brief keeps a dive — site, depth and bottom time — free, unlimited, in your own iCloud. Sites: Dive log's known list (OpenStreetMap and reviewed submissions); add your own and submit them for review. Your divers, their SCR and your sites are shared through iCloud with every Diver.Today app. DIVES BEFORE THIS ONE Up to three earlier dives, each with its surface interval. Nitrogen and helium carry over; CNS decays at a 90-minute half-time. No published table covers repetitive deco dives; your earlier profiles run through the same model. SIGNED TEAM PLANS A plan is one brief on one date with a dive lead and divers — your buddies or names you type — frozen with every figure it printed. Each diver signs by finger on your iPhone; skip anyone not there and come back to them. Send it as a picture or a one-page PDF. Plans are free and unlimited, with the app's watermark and store line. YOUR DIVE CENTER'S BRAND The Diver.Today App Family subscription puts your logo, name, two lines and color on every plan you send, without the watermark, and your color, picture and logo across the app. $2.99 a month or $19.99 a year, each with a week free, or $49.99 once for life (US prices). It covers every Diver.Today app. WHAT IT DOES NOT PLAN Rebreathers. Cave or wreck penetration. Hypoxic mixes and their travel gas. Altitude — sea level only. OTU. More than one decompression gas, a stated limit of this release. IT REFUSES RATHER THAN WARNS A gas past its oxygen limit or a surface interval under an hour gets no numbers rather than numbers with a caution. YOUR DIVE COMPUTER OWNS THE DIVE This is pre-dive arithmetic. It passes no verdict on a dive and replaces neither training, your computer nor your judgment in the water. The planner works offline. No ads, analytics or tracking. Briefs, plans, divers and sites sync through your own iCloud; nothing about you is sent to us, and a dive site only if you submit it. iPhone, iOS 17 or later. Terms of Use: https://www.apple.com/legal/internet-services/itunes/dev/stdeula/ Privacy Policy: https://diver.today/timetosurface-site/privacy.html

Decompression Engine is a fast, fully offline decompression planner for technical divers. It runs the Bühlmann ZHL-16C and VPM-B algorithms for open-circuit and closed-circuit (CCR) diving, with trimix, gas switching, multi-level and repetitive dives, gradient factors, gas planning, and CNS/OTU tracking. Three planning modes: - Recreational — no-decompression limits on air and nitrox - Technical — full decompression planning, OC and CCR, trimix and gas switches - Experimental — an unvalidated folded RGBM model, for cross-checking only Built-in safety checks flag ppO2, gas density, narcosis, isobaric counterdiffusion, out-of-range settings and aggressive conservatism, and every plan can be copied, shared or exported as text. Works entirely offline — no account, no data collection, no network required. IMPORTANT: This is a planning aid, not a dive computer. Decompression models are approximations and cannot eliminate the risk of decompression sickness. Every plan must be independently verified against your own dive computer, and this app is not a substitute for proper training and certification. You dive at your own risk.