Illustrates Bühlmann ZH-L16C tissue saturation and gas consumption across multi-level recreational profiles, with configurable conservatism, ascent profile, and Nitrox support. For educational and reference use only.
Part of the Dive Tools toolkit by Chris Uriarte
MOD at 1.4 ATA: —
Usable gas: —
If you don’t know what this is, keep it at the default.
If you don’t know what these are, keep Moderate as the default.
Use these only if you know what they mean — otherwise just choose a conservatism level above.
For NDL calculations (no decompression stops), GF High is the primary control. GF Low only affects deep-stop behavior on decompression dives.
The green-highlighted row is the gas that yields the longest effective bottom time (smaller of NDL or gas time) for this exact profile. When the dive is gas-limited, multiple mixes will tie because gas consumption depends only on depth × time (not on FO2); in that case the highlight goes to the richest tied mix, since it leaves the most NDL safety margin. The highlight is not a recommendation of the “best” or “optimal” gas — that decision also depends on your training and certifications, MOD safety margin if depth varies, CNS oxygen exposure, gas density, repetitive-dive plans, and gas availability/cost, none of which this calculator models.
This tool plans recreational, no-decompression dives by modeling two parallel constraints: (a) gas consumption from your cylinder, and (b) nitrogen tissue saturation under the Bühlmann ZH-L16C algorithm with gradient factors.
16-compartment Bühlmann ZH-L16C nitrogen model. Tissue uptake / off-gas computed via the Schreiner equation for changing depths, Haldane for level segments. Inert gas pressure uses (Pamb − PH₂O) × FN₂ with PH₂O = 0.0627 bar and FN₂ = 1 − FO₂. NDL is computed in closed form per compartment, simulating the planned ascent path (final ascent + safety stop if enabled), and taking the minimum tolerated time across all 16 compartments.
This is an educational and reference tool. It is not a substitute for proper dive training, a personal dive computer, or published dive tables. Do not use its outputs to plan or execute real dives — rely on your training, certifications, and the limits of your dive computer or trusted planning software.
THESE TOOLS ARE FOR REFERENCE PURPOSES ONLY. USE AT YOUR OWN RISK.