The Republic of Vietnam Navy (VNN; Vietnamese: Hải quân Việt Nam Cộng hòa; HQVNCH) was the naval branch of the South Vietnamese military, the official armed forces of the former Republic of Vietnam (or South Vietnam) from 1955 to 1975. The early fleet consisted of boats from France. After 1955 and the transfer of the armed forces to Vietnamese control, the fleet was supplied from the United States. With assistance from the U.S., the VNN became the largest Southeast Asian navy, with 42,000 men and women and 672 amphibious ships and craft, 20 mine warfare vessels, 450 patrol craft, 56 service craft, and 242 junks.
The origins of the Viet Nam Navy (VNN) began in 1952 with the French Navy. In 1954, in accordance with the Elysée Accords, the French handed control of the armed forces to the Vietnamese, but at the request of the Vietnamese government, continued to be in charge of the Navy until 20 August 1955. By this time the Navy numbered about 2,000 personnel, with 22 vessels. The Vietnamese then received assistance in the development of the VNN from the United States Military Assistance Advisory Group.
In 1956, the North Vietnamese began infiltrating men and arms into the Republic of Vietnam's territory by sea. In response the VNN created the Coastal Junk Force (Vietnamese: Luc Luong Hai Thuyen) of junks manned by Regional Irregular Forces and local fishermen recruited for the occasion, to patrol the waters around the Demilitarized Zone. The force later came to be known as Coastal Groups (Vietnamese: Duyen doan), and patrolled the entire 1,200-mile (1,900 km) coastline. This force was under the control of the regional military zone commands rather than the Navy, and was not incorporated into the VNN until 1965, by which time it numbered over 100 vessels.
In the late 1950s the Vietnam Navy was being modernized and developed, receiving ships and training from the United States Navy. By 1961 the VNN had a force of 23 ships, the largest of which were LSMs, 197 boats, and 5,000 men. This was insufficient to counter the growing threat of enemy infiltration and the years 1962-1964 were marked by a rapid expansion; training facilities, repair bases, and support facilities were established; communications equipment and networks improved; and organization and administrative procedures strengthened. The number of ships increased to 44 and number of personnel to 8,100.
This process continued and by the end of 1967 the personnel strength of the VNN had increased to 16,300, with 65 ships, along with 232 vessels of the River Assault Group (RAG), 290 junks, and 52 miscellaneous craft. Throughout 1968 the VNN gave priority to the improvement and expansion of their training programs in anticipation of gaining increased responsibility in the war effort as well as additional assets from the US. By the end of 1968 plans for the turnover of the majority of the United States Navy assets in Vietnam had been formulated.
In early 1969, President Richard M. Nixon formally adopted the policy of "Vietnamization". The naval part, called ACTOV ("Accelerated Turnover to the Vietnamese"), involved the phased transfer to Vietnam of the U.S. river and coastal fleet, as well as operational command over various operations. In mid-1969, the VNN took sole responsibility for river assault operations when the U.S. Mobile Riverine Force stood down and transferred 64 riverine assault craft to the VNN. By the end of 1970, the U.S. Navy ceased all operations throughout South Vietnam, having transferred a total of 293 river patrol boats and 224 riverine assault craft to the VNN.
During 1970 and 1971 the United States also relinquished control of the coastal and high seas patrols to the VNN. The U.S. naval command also transferred four Coast Guard cutters, a destroyer escort radar picket ship, an LST, and various harbor control, mine craft, and support vessels. By August 1972, the VNN took responsibility for the entire coastal patrol effort when it took over the last 16 U.S. coastal radar installations.
In addition to ships and vessels, the U.S. transferred support bases. The first change of command occurred in November 1969 at Mỹ Tho, and the last in April 1972 at Nhà Bè, Bình Thủy, Cam Ranh Bay, and Đà Nẵng. By 1973, the Vietnam Navy numbered 42,000 men and over 1,400 ships and vessels.
In 1973 and 1974, as a result of the Paris Peace Accords, the United States drastically cut its financial support for the Vietnamese armed forces. The VNN was compelled to reduce its overall operations by half, and its river combat and patrol activities by 70%. To conserve supplies, over 600 river and harbor craft and 22 ships were laid up.
On 19 January 1974, four VNN ships fought a battle with four ships of the Chinese People’s Liberation Army Navy over ownership of the Paracel Islands, 200 nautical miles (370 km) due east of Đà Nẵng. The VNN ship Nhựt Tảo (HQ-10) was sunk, Lý Thường Kiệt (HQ-16) was heavily damaged, and both Trần Khánh Dư (HQ-4) and Trần Bình Trọng (HQ-5) suffered light damage. The Chinese captured and occupied the islands.
In the spring of 1975, North Vietnamese forces occupied all of northern and central South Vietnam, and finally Saigon fell on 30 April 1975. However Captain Kiem Do had secretly planned and then carried out the evacuation of a flotilla of thirty-five Vietnam Navy and other vessels, with 30,000 sailors, their families, and other civilians on board, and joined the U.S. Seventh Fleet when it sailed for Subic Bay, Philippines. Most of the Vietnamese ships were later taken into the Philippine Navy, though the LSM Lam Giang (HQ-402), fuel barge HQ-474, and gunboat Kéo Ngựa (HQ-604) were scuttled after reaching the open sea and transferring their cargo of refugees and their crews to other ships.
VNN Fleet Command was directly responsible to the VNN Chief of Naval Operations for the readiness of ships and craft. The Fleet Commander assigned and scheduled ships to operate in the Coastal Zones, Riverine Areas, and the Rung Sat Special Zone. All Fleet Command ships were home ported in Saigon and normally returned there after deployments. When deployed, operational control was assumed by the respective zone or area commander, and the ships operated from the following ports:
The VNN was organized into two flotillas: a patrol flotilla and a logistics flotilla. Flotilla I was composed of patrol ships, organized into four squadrons. The patrol types included LSSLs and LSILs which normally operated only in Riverine Areas or the Rung Sat Special Zone; though occasionally they were assigned the four coastal zones. Operational commitments required that half of the patrol flotilla be deployed at all times, with a boat typically spending 40 to 50 days at sea on each patrol. Fleet Command patrol ships assigned to the riverine areas provided naval gunfire support as well as patrolling the main waterways in the riverine areas. One river patrol unit was assigned as convoy escort on the Mekong River to and from the Cambodian border.
Flotilla II was composed of logistic ships, divided into two squadrons, supporting the naval units and bases throughout South Vietnam. Logistic ships were under the administrative control of the Fleet Commander, and under the operational control of the VNN Deputy Chief of Staff for Logistics who acted upon orders from the Central Logistics Command of the Joint General Staff.
The 57-acre (230,000 m2) Saigon Naval Shipyard, located on the southwest bank of the Saigon River about 30 miles (48 km) from the South China Sea, represented the largest single industrial complex in South East Asia. The shipyard had been created by the French in 1863 as a major repair and resupply base. The longest-serving director was Navy Captain – Functional Navy Commodore Nguyễn Văn Lịch until the fall of Saigon on April 30, 1975. In 1969, 1,800 men were employed there, repairing and overhauling vessels, enabling the VNN to maintain its continuous patrols of the coast.