Dive Planner Pro is a dive calculator which plans scuba dives by using dive tables & formulas. Calculates: No Decompression Limit NDL. Pressure Group PG. PG after Surface Interval. Residual Nitrogen Time RNT will be added automatically. Total Bottom Time. PpO₂. O₂ exposure. More functions (only in Pro version of Dive Planner): Meter or feet. Edit Start PG. Nitrox 25-50% O₂.