Here is a detailed study of the motive forces of a yacht written in clear and accessible terms. The author has the rare gift of enabling his readers to relate the nautical phenomena with which they are so familiar to a scientific explanation of how and why these occur. The first part covers downwind sailing, upwind sailing, sails, the hull, and the dynamic motion of a yacht. Part Two is devoted to more mathematical explanations of the same phenomena for those requiring a more scientific approach.