The title is relatively straightforward. First and foremost, everyone on the water wants to stay healthy. But his is not a first aid text. Rather, this book will help you understand how the nautical environment stresses your body and what steps you can take to deal with it - to hopefully avoid needing first aid. Life on the water is different in so many ways than it is on land. Whether it is avoiding seasickness or dealing with the heat and dehydration the more you know the happier you and your crew will be. Likewise staying warm in the cold will allow you to better cope and hence better perform. Unless we are sitting around thinking about our next adventure we are always performing something (i.e. fishing, boating, cruising, or racing). If you are going to enjoy your cruise you better know what to expect in terms of hazardous marine animals or likely environmental hazards, like malaria or yellow fever. Finally, if you are to have a safe and productive voyage or adventure you must understand how maximize those basic attributes of sleep, nutrition, and exercise to keep you healthy and productive. And of course, you need to keep your brain and mind healthy which is why the last two chapter are devoted to psychology; solos sailing, group behavior, and sport and exercise psychology. If even one or two of these topics change your understanding and your behavior then this book will have been a worthwhile investment.