This fully revised and updated second edition provides worldwide coverage of an increasing variety of towing vessels, the development of ever more complex propulsion systems and how tugs are operated in their various roles. Engineer and journalist Jack Gaston reviews the fierce competition among tug operators, particularly in the ship-handling business, which has resulted in manpower cuts and the emergence of very small tugs with unprecedented power, capable of carrying out the work of vessels twice the size. This unique book will be of interest not only to marine enthusiasts but also to the towage industry and its employees.