Time to Surface

Staged decompression to 51 m on air, 21/35 or 18/45, with one deco gas — EAN50 or oxygen. Runtime, stops, minimum gas and both cylinder fills, before you kit up.

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What it plans

• 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, both adjustable
• Descent 10 m/min, 9 m/min to the first stop, 3 m/min between stops, and the last 6 m at 1 m/min — all four adjustable
• Back gas fill and turn pressure on thirds, halves or all usable
• Minimum gas: two divers on one supply, at the minimum ascent rate, stops included
• Deco bottle fill and reserve, walked level by level rather than estimated
• Metric or imperial

What it does not plan

Closed-circuit rebreathers. Cave or wreck penetration. Hypoxic mixes and travel gas. More than one decompression gas. Repetitive dives. Altitude — sea level only. It does not compute OTU or air breaks.

It refuses rather than warns

Deeper than 51 m, a gas past its oxygen limit, an exposure past the maximum, cylinders that will not cover the plan — 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.