This book is an extended and substantially updated edition of the previous book editions published in 1996 and 2013 under the same title. The 3rd edition is a one-volume, modern and comprehensive overview of the current knowledge of regular and random ocean surface waves in deep waters and in coastal zones.Since the previous editions many new theoretical advances have been made in the physical understanding and analytical and numerical treatment of various ocean wave problems. The revisions and supplements demanded by these advances have been substantial, therefore the scope of the book has been extended by adding a new chapter and substantially supplementing others.All chapters of the book have been rewritten to include and describe in detail many new discoveries made since the completion of the previous editions. In this 3rd edition a comprehensive and updated overview of the fundamentals of the regular wave mechanics, as well as the spectral and statistical properties of random waves are given. Except for the updated chapters dedicated to tsunami and extreme waves, a new chapter dealing with other types of impulsive waves starting from rest, are also included.The air-sea interaction processes as well as the last improvements in ocean wave modelling and presently available wave prediction models (WAM, WAVEWATCH III, UMWM, NEMO) are thoroughly discussed and their applications are demonstrated. The review of the present ocean observation methods encompasses the modern sea-truthing, as well as applications of data from presently operating marine satellites.In this revised edition, chapters on the behavior of surface waves in the vegetated environments such as coral reef, mangrove forest, seaweed and seagrass areas are substantially extended and updated to include the last discoveries.The explanations in the book are self-contained and detailed enough to capture the interest of the potential readers and to prompt them to explore the research literature. The list of rapidly growing number of the recent papers on the ocean waves has been extended substantially, up to about 900 titles.