In the Vietnam War, the Mobile Riverine Force (MRF) (after May 1967), initially designated Mekong Delta Mobile Afloat Force, and later the Riverines, were a joint US Army and US Navy force that comprised a substantial part of the brown-water navy. It was modeled after lessons learned by the French experience in the First Indochina War of Dinassaut and had the task of both transport (of soldiers and equipment) and combat. The primary land base was at Đồng Tâm Base Camp, with a floating base which operated in the major rivers of the Mekong Delta. Soldiers and sailors went out in river boats from the floating base to assault the Viet Cong. During part of the 1968-69 period, there were two such mobile bases operating in different parts of the Delta, Mobile Riverine Groups Alpha and Bravo. The MRF played a key role in the Tet Offensive.

A brown-water navy or riverine navy, in the broadest sense, is a naval force capable of military operations in littoral zone waters. The term originated in the United States Navy during the American Civil War, when it referred to Union forces patrolling the muddy Mississippi River, and has since been used to describe the small gunboats and patrol boats commonly used in rivers, along with the larger "mother ships" that supported them. These mother ships include converted World War II-era mechanized landing craft and tank landing ships, among other vessels.