Swift boats, officially known as Patrol Craft Fast (PCF), were 50-foot aluminum vessels used by the U.S. Navy to disrupt enemy supply lines along the coastal waters and rivers of South Vietnam. Manned by a crew of six, these shallow-draft, highly maneuverable craft were equipped with .50-caliber machine guns and mortar mounts to engage in intense, close-quarters combat. Their crucial role in coastal blockades and inland waterway patrols made them a defining symbol of the Navy's brown-water riverine operations during the war.