Operation Market Time was the United States Navy, Republic of Vietnam Navy and Royal Australian Navy operation begun in 1965 to stop the flow of troops, war material, and supplies by sea, coast, and rivers, from North Vietnam into parts of South Vietnam during the Vietnam War. Also participating in Operation Market Time were United States Coast Guard's Squadron One and Squadron Three. The U.S. Coast Guard operated under U.S. Navy command heavily armed patrol boats and large cutters that included 5-inch naval guns used in battle and gunfire support.
Radar picket escort ships, based in Guam or Pearl Harbor, provided long-term presence at sea offshore to guard against trawler infiltration. Originally built for World War II convoy duty, and then modified for distant early warning ("DEW") duty in the North Atlantic, their sea keeping capability made them ideal for long-term presence offshore where they provided support for Patrol Craft Fast (PCF) boats, pilot rescue and sampan inspection. There were two or three on station at all times. Deployments were seven-months duration, with a four- or five-month turn-around in Pearl. When off station, they alternated duty as Taiwan Defense Patrol, with stops in Subic and Sasebo for refit mid-deployment.
Operation Market Time was one of six Navy duties begun after the Tonkin Gulf Incident, along with Operation Sea Dragon, Operation Sealords, Yankee Station, PIRAZ, and naval gunfire support.
Background
When a trawler was intercepted landing arms and ammunition at Vung Ro Bay in northern Khánh Hòa Province on 16 February 1965, it provided the first tangible evidence of the North Vietnamese supply operation. This became known as the Vung Ro Bay Incident. Operation Market Time was established by the United States Joint Chiefs of Staff at the request of General William C. Westmoreland, commanding general of Military Assistance Command Vietnam. He requested that the U.S. Navy establish a naval blockade of the vast South Vietnam coastline against North Vietnamese gun-running trawlers. The trawlers, usually long Chinese-built steel-hulled coastal freighters, could carry several tons of arms and ammunition in their hulls. Not flying a national ensign that would identify them, the ships would maneuver "innocently" out in the South China Sea, waiting for the cover of darkness to make high-speed runs to the South Vietnam coastline. If successful, the ships would off load their cargoes to waiting Việt Cộng (VC) or People's Army of Vietnam (PAVN) forces.
At the time of inception, the Coast Guard contributed seventeen Point-class cutters while the Navy added approximately fifty ships known as Patrol Craft Fast (PCFs or Swifts) that could reach a maximum speed of 28 knots. In detail, on 16 April 1965 United States Secretary of the Navy Paul Nitze requested Coast Guard assistance with Market Time. On 6 May 1965, the seventeen Point-class cutters were loaded as deck cargo on merchant ships in New York City, Norfolk, New Orleans, Galveston, San Pedro, San Francisco and Seattle for transport to U.S. Naval Base Subic Bay. At Subic Bay each of the cutters was armed with an 81 mm mortar and five .50 caliber machine guns. Coast Guard Squadron One was organized into Division Eleven with eight of the cutters and Division Twelve with nine of the cutters. Division Twelve sailed on 15 July 1965 and arrived at Đà Nẵng on 20 July. Division Eleven sailed on 20 July and arrived at An Thoi on 31 July. An additional nine cutters were provided to form Division Thirteen at Vũng Tàu in early 1966. Each cutter with an eleven-man crew would spend four days on patrol followed by two days alongside a support ship. All 26 cutters were turned over to South Vietnamese crews between 16 May 1969 and 15 August 1970.
Operations
Coastal surveillance centers
In an effort to coordinate all coastal interdiction activities, coastal surveillance centers (CSC) were established at Da Nang, Qui Nhon, Nha Trang, Vung Tau and An Thoi and were manned by Republic of Vietnam Navy (RVNN) and U.S. Navy watchstanders. Reports of possible sightings of suspect vessels from aircraft and watercraft were reported to the CSC's and the appropriate response vessels and aircraft were dispatched to the scene by CSC personnel.