You will find in this book some valuable and reliable lessons about safe diving. The editors of and authors of this book are a cadre of scientists and physicians with broad experience and knowledge of diving physiology and decompression theory. As is often the case, it requires a group effort to succeed in advancing practical knowledge. The colloquialism "the whole is greater than the sum of its parts" is often true and the PHYPODE Reasearch Group epitomizes this concept. By logically grouping the various elements of diving science and medicine with provocative "food for thought" sections, the text offers valuable lessons to those interested in the current state of diving. Despite nearly 170 years of reasearch, the fundamenal nature of decompression stress remains elusive. As is well outlined in this book, great advances have been made to the practical elements allowing for safe diving. Nonetheless, there are glaring voids of knowledge related to the nature of bubble nucleation, its consequences and methods to ameliorate risk. The synergy exhibited in this text not only provides a foundation for what is known, it offers a glimpse of where research is taking us. - Professor Stephen R. Thom, Dept. of Emergency Medicine, University of Maryland School of Medicine This is a book for all diving fans who want to discover their passion through a scientific approach. EXCERPT Decompression illnesses (DCI), or as they are called more scientifically: dysbaric disorders, represent a complex spectrum of pathophysiological conditions with a wide variety of signs and symptoms related to dissolved gas and its subsequent phase change.1, 2 Any significant organic or functional dysfunction in individuals who have recently been exposed to a reduction in environmental pressure (i.e., decompression) must be considered as possibly being caused by DCI until proven otherwise. However, apart from the more obvious acute manifestations of a single, sudden decompression, individuals who have experienced repetitive exposures (e.g. commercial or professional divers and active recreational divers) may also develop sub-acute or chronic manifestations, even if subtle and almost symptomless.