The USS Tucumcari (PGH-2) was a Boeing-built hydrofoil. Named after Tucumcari, New Mexico, it was the basis for the technology used in the subsequent Pegasus-class patrol boats and the Jetfoil ferries. Its unique feature was a waterjet propulsion and a computer-controlled fully submerged foil configuration of one foil at the bow and foils on the port and starboard sides. The Tucumcari was one of two prototype boats contracted by the Navy under project SCB 252 for the purpose of evaluating the latest hydrofoil technology. The second boat was the rival Grumman-built USS Flagstaff (PGH-1). Construction, operations in San Diego, and deployment to Vietnam The first waterjet propelled Patrol Gunboat Hydrofoil Tucumcari (PGH-2) was built for operation by the Navy at a cost of $4 million by a Boeing subcontractor in Tacoma, Washington, and then assembled and outfitted at a Boeing facility in Seattle. Boeing's previous US Navy operated hydrofoil was the Patrol Craft Hydrofoil , which utilized two forward hydrofoils and propellers on an aft-mounted single foil. Before that, Boeing had built and operated several hydroplane and hydrofoil test craft for itself and for the Navy. The assembly and outfitting of Tucumcari began on 1 September 1966 at the Advanced Marine Systems Division of the Boeing Aerospace Group. Tucumcari was launched on 15 July 1967, and delivered to the Navy on 8 March 1968. Placed "in service with an officer-in charge" as a patrol boat (vs. "commissioned" as a ship with a commanding officer) on that day, the ship's first officer-in-charge was Navy Lieutenant Martinn H. Mandles. Tucumcari, an extremely fast, highly maneuverable, prototype hydrofoil gunboat designed to perform well even in heavy weather, represented the culmination of 10 years of hydrofoil development. The new gunboat arrived at Naval Amphibious Base Coronado, California, her home port, in July 1968. She conducted operational evaluation tests and participated in exercises with the U.S. Pacific Fleet. In addition, she conducted day and night operations with Fleet ships ranging from cruisers to conventional patrol craft. After a year of operating out of Coronado, Tucumcari was deployed to South Vietnam. She spent most of her six months in the combat zone assigned to Operation Market Time, the coastal patrol established to stop the flow of supplies from North Vietnam. While performing this duty, she logged 200 hours of foilborne operations including day and night, all-weather, and high sea state missions. She also conducted underway replenishments