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.