Applies Boyle’s, Dalton’s, Henry’s and Charles’s laws quantitatively to a diver. Covers unit conversion across fsw, msw, ata, psi, bar and mmHg; volume change with depth and why the shallowest 33 feet carry the greatest fractional change; partial pressures on air and nitrox; inert gas loading and off-gassing; gas density and the work of breathing; and altitude exposure after diving.