Huge advances in electronic navigation since the original publication of Celestial Navigation have transported offshore navigators to a world of press-button convenience. Traditional navigation skills--and technology-free position finding--are still vital, though, especially when things go wrong, as they will: batteries fail, antennas go overboard, and electronics get wet. Knowledge of celestial navigation is a life-saving emergency skill; it is also a rite of initiation and its practice still a favorite pastime among serious cruisers. A bestseller for over 65 years, Celestial Navigation for Yachtsmen is a model of simplicity and clarity. The only mathematics involved are addition and subtraction, which explains why this book has truly earned its reputation for admirable conciseness and for making a tricky subject easy to understand. This edition has been thoroughly revised by Andy Du Port, the highly respected past editor of Reeds Almanacs.