Taken on strength by the USMC in 1961 as an HUS-1 just before resignation as UH-34D next year and deployed aboard USS Guadalcanal in 1964 with HMM-261. Saw service in Vietnam in 1965/66 and entered the museum in 1973. In 1990 it was painted orange as HUS-1L BuNo 144657 'XO-657', one of four modified for operations by VX-6 in Antarctica and setting a record with a 450-mile flight in 1957. By 1998 repainted in standard USMC colours to represent the Ugly Angels of HMM-362, which in 1962 was the first Marine helicopter squadron to deploy to Vietnam

Part of the Vietnam Experience at Patriots Point. Unlike the H-34 Choctaw of the US Army, the USMC Seahorse did see action in Southeast Asia.