Map of Vietnam

Coastal Interdiction

The primary objective of the Market Time coastal patrol was to prevent the enemy from strengthening his forces in South Vietnam through seaborne infiltration of supplies and munitions. The North Vietnamese Naval Transportation Group 125 used steel-hulled, 100-ton trawlers and seagoing junks to infiltrate the South. The Viet Cong operated smaller junks, sampans, and other craft within South Vietnamese coastal waters, and limiting this movement also became a responsibility of the Market Time forces.

The coastal surveillance operation was organized around nine (initially eight) patrol sectors covering the 1,200-mile South Vietnamese coast from the 17th parallel to the Cambodian border and extending 40 miles out to sea. Within these areas, ships and craft of the U.S. Navy searched for contraband. American aircraft operating from ships offshore and from bases in South Vietnam, Thailand, and the Philippines flew search patterns over the Market Time area. By 1968 the patrol generally was divided into three zones: (1) an air surveillance sector farthest out to sea; (2) an outer surface barrier patrolled by large U.S. ships; and (3) an inner, or shallow-water, barrier patrolled by U.S. and South Vietnamese boats and craft and Coastal Force junks. Mobile units of Inshore Undersea Warfare Surveillance Group 1, Western Pacific Detachment, deployed to South Vietnam in April 1966 to form an additional screen.

Market Time forces aided the allied cause in other ways. The naval gunfire support offered by these American and Vietnamese ships and craft often was of vital importance to ground units locked in combat. The naval units also served as blocking forces in encirclement operations conducted near the coast and on large rivers. The transportation of friendly troops and the evacuation of civilians constituted other important tasks. And, as with most American forces in South Vietnam, the Market Time units worked to win friends for the allied cause by building schools, donating food and clothing, and performing other civic actions.

During the first half of 1965, the Seventh Fleet operationally controlled the Vietnam Patrol Force (Task Force 71), the American component of Market Time. The Naval Advisory Group, headquartered in Saigon, served as the liaison between the fleet, COMUSMACV, and the South Vietnamese Navy. The five U.S.-Vietnamese coastal surveillance centers set up at Danang, Qui Nhon, Nha Trang, Vung Tau, and An Thoi coordinated actual operations. To improve mutual understanding and communication, U.S. and Vietnamese naval officers sailed in the vessels of the other service.

On 31 July 1965, formal control of the American Market Time force passed from the Seventh Fleet to the Naval Advisory Group, which in turn activated the Coastal Surveillance Force (Task Force 115). The fleet continued to provide logistic and administrative support. The command function was further refined on 1 April 1966 when Naval Forces, Vietnam, was established, relieving the NAG of responsibility for Market Time operations. In addition, the naval support activities at DaNang and Saigon took over logistic and administrative duties. The next year, in July, Commander Task Force 115 moved his headquarters from Saigon to Cam Ranh Bay.

The years 1965 to 1968 witnessed a great increase in Market Time resources and the full development of patrol tactics and operating procedures. During the first months of the patrol in 1965 an average of 15 destroyers or minesweepers steamed off South Vietnam, with a least one ship assigned to each of the sectors. Soon, however, radar picket escorts (DER), with better fuel efficiency and electronic equipment, replaced the destroyers. Furthermore, to help the Vietnamese Navy’s Coastal Force and Sea Force (American naval leaders were dissatisfied with their operational performance), in June the U.S. coast Guard began dispatching 82-foot cutters (WPB), eventually totaling 26, to Southeast Asia. The operational chain of command extended from Commander Task Force 115 through Commander Coast Guard Activities, Vietnam (established on 3 February 1967) to Coast Guard Squadron 1. This latter command controlled Coast Guard Division 11 stationed at An Thoi, Coast Guard Division 12 at Danang, and Coast Guard Division 13 at Cat Lo. To augment the inshore patrol, the Navy bought 84 Swift (PCF) boats designed by the Louisiana-based Stewart Seacraft Company and deployed them to South Vietnam. These 50-foot, 23-knot vessels, armed with .50-caliber machine guns and an 81-millimeter mortar, became the mainstays of the Navy’s Coastal Surveillance Force. Under Boat Squadron 1 (later Coastal Squadron 1), Boat Division 101-105 (redesignated Coastal Divisions 11-15 on 1 January 1967) operated from bases at An Thoi, Danang, Cat Lo, Cam Ranh Bay, and Qui Nhon, respectively. In June 1967 the Navy activated an additional Swift boat unit, Coastal Division 16, at Chu Lai in I Corps.

The harbor defense and surveillance units in the ports of Vung Tau, Cam Ranh Bay, Qui Nhon, Nha Trang, and Vung Ro, Inshore Undersea Warfare Groups (IUWG) 1, 2, 3, 4, and 5, operated a total of 16 large personnel landing craft, 25 Boston Whalers, and 8 picket boats in Operation Stable Door. The 45-foot picket boats, which began to reach Vietnam in June 1967, carried a crew of one officer and five men and two .50-caliber machine guns, twin-mounted. In each port the units constructed harbor entrance control posts and equipped them with radios and surface search radars.

During 1967 and 1968, the continuing demand for Market Time vessels resulted in the deployment of 15 Coast Guard high endurance cutters (WHEC) to South Vietnam. Operating under Coast Guard Squadron 3, activated with the first deployments in the spring of 1967, the WHECs added their search radars, one 5-inch/38-caliber gun, six .50-caliber machine guns, and two 81-millimeter mortars to the patrol’s firepower.

Beginning in 1967, the newly built Asheville-class patrol gunboat (PG), designed specifically for coastal operations in the Third World, made its first appearance in Southeast Asia. That March, Commander Coastal Squadron 3 began surveillance of South Vietnam’s coast with Gallup (PG 85). Coastal Flotilla 1 was then created to direct the operations of this unit and the new Coastal Squadron 1, with Asheville (PG 84) and Crockett (PG 88). The 165-foot PGs capable of 37-knot speeds, carried one 3-inch/.50-caliber gun forward, one 40-millimeter gun aft, and four .50-caliber machine guns. At first Plagued by mechanical and repair part replacement problems, the shallow-draft and well-armed PGs became a useful Market Time resource. But hydrofoil gunboats Flagstaff (PGH 1) and Tucumcari (PGH 2), assigned to Task Force 115 later in the war, proved not as satisfactory in operation. These revolutionary vessels were unsuited to patrols in the rough seas off Vietnam and were too mechanically complex for the repair facilities in the combat theater.

Various aircraft flew aerial surveillance of South Vietnam’s coastal waters. For a brief time in 1965 A-1 Skyraiders operating from carriers at Dixie Station covered the central Vietnam coast. This mission was shared and then taken over by a patrol squadron based at Sangley Point in the Philippines and equipped with the advanced P-3 Orion aircraft. Throughout this period, five to seven P-2 Neptunes stationed at Tan Son Nhut near Saigon ranged up and down the South Vietnamese littoral along designated patrol tracks. In addition, from May 1965 to April 67, Martin P-5 Marlin seaplanes operated from seaplane tenders Currituck (AV 7) and Salisbury Sound (AV 13), periodically anchored at Condore and Cham islands and at Cam Ranh Bay. To compensate for withdrawal of the older seaplanes in early 1967, the Navy stationed a squadron of 12 P-2’s ashore at Cam Ranh Bay and a detachment of P-3’s at Utapao in Thailand. The P-3s patrolled the Gulf of Siam. On an intermittent basis, U.S. Army Bird Dog observation aircraft and South Vietnamese Douglas C-47s watched over several critical coastal sectors.

To improve the effectiveness of the anti-infiltration system, the Navy emplaced surface search radars on Son and Obi islands south of the Mekong Delta and on Re island east of Chu Lai and upgraded communications between headquarters, coastal surveillance centers surface ships and craft, and aircraft. Greater use of junks and sampan identification manuals, South Vietnamese identity papers, and passes for fishermen tightened the coastal net. MACV intelligence also focused more attention on the Communist maritime effort.

There was scant evidence in 1965 of Communist seaborne infiltration. After the Vung Ro incident in February, the allies detected not one trawler closing the shore. Relatively few of the junks and smaller craft stopped and searched in shallow water were found to carry enemy personnel or contraband. During this period, however, the patrol was not functioning with maximum effectiveness because the Americans and the South Vietnamese concentrated on refining patrol responsibilities, search sectors, operational tactics, command and communications procedures, and other essential matters. Furthermore, while the number of vessels in the command increased, the total still was insufficient for complete coverage of South Vietnam’s coastal waters.

On the evening of 31 December 1965, however, Hissem (DER 400) detected a small trawler heading for shore off the Ca Mau Peninsula. When the trawler’s master knew the allies had spotted his ship, he turned it around and headed north, aborting the mission. The first concrete success of the new program occurred in May 1966 when Market Time forces intercepted and destroyed another infiltrating trawler on the coast of An Xuyen Province. The vessel’s recovered cargo consisted of mortar and small arms ammunition manufactured in the People’s Republic of China during 1965. Again in June, Task force 115 units tracked a steel-hulled vessel that fired on Coast Guard cutter Point League (WPB 82304) before running aground on the south coast of the Mekong Delta. In addition to the damaged ship, the Vietnamese-American defense force captured over 100 tons of munitions destined for the Viet Cong. In December 1966, the Coastal Surveillance Force detected another trawler headed for Binh Dinh Province and forced it to abandon its mission. On the first day of the new year, Swift boats from Coastal Division 13 and Coast Guard cutter Point Gammon (WPB 82328) gave chase to a Communist vessel, compelling the crew to blow up their ship near the mouth of the Bo De River. Completing the year’s tally, in March and then in July, Market Time aircraft, ships, and craft prevented two steel-hulled trawlers from landing their cargo on the beaches near Quang Ngai.

During this lucrative period of the Market Time patrol from January 1966 to July 1967, many enemy junks and sampans were destroyed, captured, or forced to abort their missions. Most American and Vietnamese patrol vessels now were deployed to coastal waters and functioned with relative efficiency. The combined patrol force inspected or boarded over 700,000 vessels in South Vietnamese coastal waters.

From July to the end of 1967, the allies detected no trawlers attempting infiltration. Then, in February 1968, in an apparently desperate attempt to supply Viet Cong forces fighting for survival in the aftermath of the Tet Offensive, the enemy dispatched five ships into South Vietnamese waters. Nearing his destination, the master of the first ship gave up the attempt and shaped course for home. Task Force 115 units forced another ship aground near Danang, where the crew scuttled her. Under fire from American vessels off Ca Mau, a third trawler exploded and sank. The allies forced another ship to beach northeast of Nha Trang and then destroyed her with gunfire. The last ship, spotted from the air out to sea, reversed course and returned north. Following this serious setback for the enemy the Market Time patrol did not discover another infiltrating trawler until August 1969.

Aside from this crisis-related gamble at Tet, by 1968 the North Vietnamese were deterred from the use of this avenue of seaborne infiltration as a major means of supply. The Coastal Surveillance Force was increasingly effective at intercepting larger vessels and even the more numerous but low cargo capacity junks and sampans.

Other factors contributed indirectly to the success of Market Time. From November 1966 on, the Sea Dragon operation off North Vietnam reduced the enemy’s coastal traffic. At the same time, the Communists developed less costly and more efficient means for supplying their forces in the South. Beginning in December 1966, and with the tacit agreement of Prince Norodom Sihanouk, the Cambodian head state, the enemy began using the port of Sihanoukville in the supposedly neutral country as a secure transshipment point for munitions destined for the Mekong Delta battleground. Not wanting to widen the war, President Johnson refused to authorize any allied operation to close the port to Communist shipping. In addition, the Ho Chi Minh Trail had become a well-established supply complex that sustained Viet Cong and North Vietnamese units in the I and II Corps Tactical Zones. Nonetheless, the Market Time patrol accomplished it primary mission by deterring the enemy’s use of the sea to support the political-military offensive against South Vietnam.

Minesweepers that Served during the Vietnam War

All of these small craft served in Vietnam and around Vietnam from 1960 until “Operation End Sweep” at the end of the War