A Coast Guard cutter cruises along the coast as part of Operation Market Time. (USN K-31519)

Sea and river travel had always been important in South Vietnam and there were an estimated 60,000 junks, sampans and trawlers on its coastal waters, rivers and canals. US Navy’s Vietnam Patrol Force, Task Force 71, was organized in March 1965 to stop the Viet Cong ferrying supplies on the sea and along rivers. Operation Market Time coordinated US Navy and US Coast Guard movements with the South Vietnamese Navy Junk Force, controlling operations on land, sea and air along 1,200 miles of coastline.

Coast Guard Squadron One (Ron One) arrived in July 1965 with seventeen 82ft patrol boats and two support boats crewed by officers and men trained in coastal surveillance techniques. It was split into two divisions and while Division 12 covered the east coast from Da Nang, Division 11 patrolled the west coast from An Thoi in the Gulf of Thailand. Task Force 71 was renamed Coastal Surveillance Force, Task Force 115, at the same time and it set up five Coastal Surveillance Centers at Da Nang, Qui Nhon, Nha Trang, Vung Tau, and An Thoi. Minesweeper and destroyer escorts assisted with offshore navigation while Vietnamese junks monitored the shallow waters; Special Forces teams often accompanied patrols.

Naval forces operating in the shallow coast waters and along the rivers across South Vietnam were controlled by the Commander Naval Forces, Vietnam, after April 1966 and Task Forces were divided as follows:

Task Force 115: Coastal Surveillance Force covered the shallow waters along the coast

Task Force 116:River Patrol Force carried out routine patrols of waterways

Task Force 117:Riverine Assault Force was equipped to undertake offensive operations

The Commander was also responsible for Naval Support Activity, Saigon, supplying naval forces across the country (III Marine Amphibious Force controlled the Naval Support Activity covering I Corps from Da Nang) and both the Seebees and civilian contractors working on naval construction projects.


Task Force 115 split the coast into nine sectors, each with three observation zones:

Air Surveillance Zone: Planes identified and photographed targets up to 150 miles from the coast and reported them to the Coastal Surveillance Centers.

Deep Water Zone: US Navy and Vietnamese destroyers and minesweepers patrolled a 40-mile zone, searching trawlers.

Shallow Water Zone: US Navy Coast Guard patrol boats and South Vietnamese junks patrolled out to a 12-mile limit, searching trading and fishing vessels.

Market Time’s priorities were to search craft in the following order:

Vessels passing through an area

Junks fishing or operating in local areas

Anchored fishing boats

Working fishing boats

Squadron One searched over 65,000 craft during the first twelve months, seizing over 100 tons of supplies and arresting dozens of suspects. The patrol boats also aided craft in distress, rescued downed pilots and seamen from the water, guided lost craft and escorted survey boats along the coast and rivers; they also covered many of the Navy’s patrols during the monsoon season.

Another nine patrol boats arrived in February 1966 and they formed Division 13. It was based at Cat Lo and patrolled the Mekong Delta and the Rung Sat Special Zone. After August 1966 the patrol boats also started visiting inhabited islands off the coast to search for Viet Cong bases. During their visits they handed out government literature, administered medical treatment and promoted building projects. Cam Ranh Bay became the center of coastal air patrol operations in April 1967 with the establishment of the US Naval Air Facility with its P-2 Neptune and P-3 Orion patrol aircraft. Coastal Surveillance Force staff moved to the base a few months later and while the Naval Communications Station improved control of Operation Market Time, a new pontoon dock was built for repairing coastal patrol vessels.

The patrol boats were not designed for extended patrols and they only had a restricted range with a limited capacity for ammunition and supplies; living conditions were also austere, particularly on high seas. Five high-endurance cutters arrived in May 1967 to improve the patrols’ effectiveness and they formed Coast Guard Squadron Three. Ron Three, as it was known, patrolled the Gulf of Thailand from Song Ong Doc. Royal Australian Navy craft also joined Market Time in 1967.

One of the cutters was assigned as logistical support for Squadron One. The crew quarters were used as a rest center, allowing crews to work in shifts, while the patrol boats were supplied with stores delivered by passing ships. An onboard medical officer dealt with injuries and sickness for ships in the area. Ron Three also surveyed the coastline and charted the shallow waters.

Modern cutters with improved gunfire control and crew quarters arrived in October 1969 and a flight deck allowed helicopters to deliver fuel, supplies and personnel. Vietnamization began at the beginning of 1969 when the Vietnamese Navy started training with the Squadrons and the last of the cutters were handed over at the end of 1971.

The Viet Cong’s seaborne supply routes had been virtually brought to a standstill by 1967 and attempts to revive them in 1969 failed. Over 8,000 Coast Guardsmen served in Vietnam and their craft covered over 5.5 million miles. Over 900,000 vessels had been reported and over 250,000 had been boarded or inspected. The Coast Guard also detained over 10,000 suspects and killed or wounded nearly 2,000 Viet Cong in fire-fights.


The coast of South Vietnam could be treacherous and the outdated charts were of little use to the crews of the transport ships bringing supplies to the ports. A tender set buoys for offloading fuel at the four main ports in the spring of 1966 before marking safe passages through the coral reefs and sandbars. It also worked with the dredgers, marking channels and moorings with the help of a landing craft.

The Coast Guard took over in May 1967, surveying sea channels and setting off-shore firing range boards for aviation and naval units. It also established the Long-range Aid to Navigation system (or LORAN) so sailors and pilots could safely navigate over the sea during bad weather.


Coast Guard Merchant Marine Details were organized in December 1966 to take over control of discipline at the ports, establishing law and order on the dockside. They handed over to the United States Consular Missions when the ports were scaled down. Thousands of tons of ammunition were delivered to the US ports along the coast and trained Port Security and Explosives Loading Detachments taught US Army and Vietnamese stevedores how to unload and store their dangerous cargo. They also regulated the delivery of ammunition to inland bases by landing craft.

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