An Azimuthing Stern Drive (ASD) tug or towboat is a high-performance vessel that is responsive, quick to maneuver and extremely powerful. In the hands of a skilled operator maneuvering these vessels looks effortless and seamless - smoothly spinning around, nimbly shifting position, having pinpoint control, all while the operator's hands move the control handles instinctively and naturally. This book takes the reader through an efficient learning sequence leading to that level of proficiency. Text, illustrations and practice drills create a clear understanding of ASD maneuvering principles and assist the reader in acquiring the intuitive hands-on feel required to operate these vessels. Each chapter covers a basic maneuvering element - steering, managing speed, stopping, hovering, lateral movement - and their application to light boat, barge and ship handling. This book is the first step for a professional mariner adding a new competency to his or her art of towing - driving a Z-drive. AUTHOR: Captain Slesinger is a captain of oceangoing and harbour tugs and a maritime consultant. He is committed to promoting the professionalism of the brown and blue water mariner and creating innovative maritime business, safety, and training solutions. . The book creates a learning pathway to acquire the skills of a Zdrive tugmaster . This book creates a mind and hands-on understanding through text and illustrations of the skills required to master a Z-drive . A Z-drive propelled tug or towboat raises the level of challenge and reward for the professional tugmaster 176 images and illustrations