An interdisciplinary field of study, underwater life support systems design requires the application of engineering principles with a knowledge of human physiology. Specifically, the study of life support systems design should have a strong background in the following areas: human physiology related to respiration and the thermo-regulatory system underwater physics including the interrelationship of pressure and temperature to gas volumes, their properties, and their solution in other materials the chemistry involved in the absorption of gas constituents including carbon dioxide and other toxic contaminants decompression theory required to predict the safe exposures to elevated pressure environments pressure vessel design including design methods for exposures to both external and internal pressures heat transfer including conduction, convection, and radiation modes fluid dynamics involved in hydrostatic pressures and pipe flow psychrometry at elevated pressures required to maintain adequate moisture levels in cabin environments