This book examines the interaction between ocean waves and oscillating systems. Topics covered include the background mathematics of oscillations, gravity waves on water, the dynamics of wave-body interactions, and the absorption of wave energy by oscillating bodies. Linear algebra, complex numbers, differential equations, and Fourier transformation are utilized as bases for the analysis, and each chapter ends with problems. While the book's focus is on linear theory, the practical application of energy storage and transport is interwoven throughout. Graduate students and researchers will find it an excellent source of wave energy theory and application. A solutions manual is available for instructors.