While the effects of pressure change are readily quantified in physics, chemistry, and engineering applications, the physiology, medicine, and biology of pressure changes in living systems are much more complicated. This complex science translated to technical diving is discussed in a five-part series, with each topic self-contained and strategically developed in relationship to diving, spanning many disciplines and focusing on a number of technical areas. A suite of application exercises is provided at strategic points in the text. Additional material focusing on diving data, statistical correlations, underwater tests, and risk is included.