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Plan safe recreational scuba dive profiles from air supply, depth, and SAC rate. Estimate bottom time, turn pressure, and remaining gas at ascent.
Calculate enriched air nitrox MOD, EAD, and partial pressure of oxygen (ppO2) for scuba diving. Plan safe oxygen exposure limits at depth.
Calculate scuba air usage rate at depth from SAC rate and dive depth. Estimate PSI per minute, cu ft consumed, and remaining dive time from tank pressure.
Decompression algorithms track theoretical tissue compartments saturating with inert gas during exposure. Each compartment has an M-value slope (b) and intercept (a) defining maximum tolerated pressure during ascent.
M-value = a + b × P_ambientGradient factors (typically GF 30/70 to 85/85) scale M-values conservatively. Lower GF_low values add deep stop time; GF_high controls surfacing tolerance.
Ceiling depth = f(GF_low, GF_high, tissue loading)As ascent proceeds, tissue pressure drops and ceilings shallow. The algorithm integrates stop times at each depth until all compartments are within safe limits at the surface.
Total deco time = Σ stop duration at each ceiling depthUpdated: July 2026
A wreck penetration at 130 ft for 45 minutes on air requires substantial decompression — often 20–40 minutes of staged stops starting at 70–90 ft depending on gradient factors.
Switching to 50–100% oxygen at 20 ft accelerates off-gassing. The calculator shows base deco obligation before accounting for nitrox/oxygen acceleration benefits.
After a deco dive, residual nitrogen/helium loading affects the second dive. Plan surface intervals of 4+ hours or use the calculator with residual loading for back-to-back tech dives.
Technical and decompression diving requires staged ascents with mandatory stops to off-gas dissolved inert gas safely. Enter bottom depth, time, gas mix, and gradient factors to estimate required decompression stop depths, durations, and total ascent time.