In 1965 the military situation in the Mekong River Delta of southern Vietnam had deteriorated to such a degree that the decision was made to commit a joint US Army and Navy Mobile Riverine Force to the area. This force was unique in its composition, mission, and the means by which it operated – riverine craft. Comprising the Army’s 2d Brigade, 9th Infantry Division, and the Navy’s River Assault Flotilla One, it used a variety of watercraft, including heavily modified landing craft, purpose-built patrol boats, and a whole host of auxiliary and support craft. This book explores those craft, and also gives an account of Task Force Clearwater, a much smaller operation in the extreme northern part of South Vietnam.