The River Patrol Force commander led other naval forces, including the highly trained and skilled SEALs. By mid-1968, the 211-man SEAL Team 1, based at Coronado, fielded twelve 14-man platoons, each composed of two squads. Generally four or five of the platoons at any given time were deployed to South Vietnam, where one or two of them served with the special operations force in Danang and another three operated from Nha Be as Detachment GOLF in support of the Task Force 116 campaign in the Rung Sat Special Zone. Beginning in early 1967, the Atlantic Fleet's SEAL Team 2 provided another three platoons, two of which were stationed with the Game Warden units at Can Tho. These units launched SEAL operations in the central delta area. Although focused primarily on the areas to the south and west of Saigon, the SEALs also mounted operations in the I and II Corps Tactical Zones.
These elite naval commando units carried out day and night ambushes, hit and run raids, reconnaissance patrols, salvage dives, and special intelligence operations. Normally operating in six-man squads, the SEALs used landing craft, SEAL team assault boats (STAB), 26-foot armored trimarans, PBRs, sampans, and helicopters for transportation to and from their target areas. Mobile, versatile, and extremely effective in their dangerous work, the SEALs were a valuable fighting force in the riverine environment of Vietnam.
Mine clearance forces also were essential to the security of Vietnam's waterways. Nowhere was this more crucial than on the rivers near Saigon, the country's most vital port. Viet Cong mining of the main shipping channel, the Long Tau River, which wound its way through the Rung Sat Special Zone south of the capital, could have had a devastating effect on the war effort. Consequently, on 20 May 1966, the Navy established Mine Squadron 11, Detachment Alpha (Mine Division 112 after May 1968) at Nha Be, under Commander Task Force 116. From 1966 until mid-1968, the minesweeping detachment operated 12 or 13 minesweeping boats (MSB) reactivated in the United States and shipped to Southeast Asia. The 57-foot, fiberglass-hulled vessels were armed with machine guns and grenade launchers and carried surface radars and minesweeping gear for clearing explosives from the key waterways. The Navy also deployed three-boat subordinate units to Danang and Cam Ranh Bay. Detachment Alpha's strength increased in July 1967 when the first of six mechanized landing craft (LCM(M)) that were specially configured to sweep mines arrived at Nha Be.
Game Warden operations got underway in early 1966. Naval leaders set out to secure the vital water passages through the Rung Sat and to establish patrols on the large Mekong Delta rivers. On these latter waterways, the Viet Cong transported arms and supplies brought in from Cambodia, shifted guerrilla units, and taxed the population. The Navy created two separate task groups to direct operations in the respective areas.
On 26 March 1966, U.S. Navy, U.S. Marine, and South Vietnamese forces kicked off Operation Jackstay, the war's first major action in the Rung Sat. PBR units (including one section from Tortuga), minesweeping boats from Nha Be, SEALs, and helicopters operated together to sweep the area. At the end of the 12-day effort, the allies had killed or captured 69 of the enemy; destroyed Viet Cong supply bases, training sites, and other logistical facilities; and, at least for a time, restricted enemy movement in the zone.
The enemy, however, remained a potent threat. In one month, August 1966, Viet Cong mines in the Long Tau heavily damaged SS Baton Rouge Victory, a Vietnamese Navy motor launch minesweeper, and MSB 54. In November, a Viet Cong mine sank MSB 54. And on the last day of the year, American forces discovered a Soviet-made contact mine in the shipping channel. The Americans and the South Vietnamese intensified minesweeping operations and the enemy continued to fight back. In February 1967 Communist recoilless rifle fire and mines destroyed MSB 45 and heavily damaged MSB 49.
By the spring of 1967 the rapid buildup of allied forces in the Rung Sat area, the refinement of tactics, and improvement of weapon systems began to reduce enemy effectiveness. During the year Vietnamese Regional Force and U.S. Army 9th Division troops conducted aggressive sweeps ashore in coordination with the helicopter, PBR, and MSB units; the better equipped LCM(M)s augmented the minesweeping force at Nha Be. SEALs began sowing mines throughout enemy-held areas, and both PBRs and MSBs added rapid-fire, 40-millimeter grenade launchers to their armament. From mid-1967 to mid-1968, the Viet Cong continued to ambush shipping on the Long Tau with mines, 122-millimeter rockets, rocket-propelled grenades, recoilless rifles, machine guns, and small arms. Quick action by allied reaction forces, however, often cut short these assaults. Thus, ship damage and personnel casualties were relatively light. Other attacks never occurred because PBR and SEAL patrols upset enemy plans or the MSBs and LCM(M)s swept up mines. Consequently, the Communists were unable to sever the vital lifeline to Saigon, even when their forces were fighting for survival during the Tet and post-Tet battles of 1968.
Game Warden operations in the central reaches of the Mekong Delta began on 8 May 1966 when PBR River Section 511 of River Division 51 at Can Tho patroled a stretch of the Bassac River. Soon afterward, other units initiated surveillance of the upper Mekong and the My Tho, Ham Luong, and Co Chien arms of the mighty river that emptied into the South China Sea.
In two-boat random patrols Task Force 116 sailors checked the cargo and identity papers of junks and sampans plying the waterways, set up night ambushes at suspected enemy crossing points, supported the SEALs with gunfire and transportation, and enforced curfew restrictions in their sector, usually no more than 35 nautical miles from the base.
Game Warden operations in the central delta registered only modest success from 1966 to 1968. Only 140 PBRs were on station to patrol many miles of river and canal. As a result, they could canvass only the larger waterways. Still, the Task Force 116 patrol forced the Viet Cong to divert troops and other resources to defense and to resort to less efficient transportation on smaller rivers and canals. During 1966 the task force refined its tactics, evaluated the performance of its boats and weapons in combat, and regularized its operational procedures. At the same time naval leaders repositioned the LSD and LST support ships inland because heavy seas at the river mouths made operations from there difficult. The year 1967 opened with the accidental loss of a PBR during launching operations from Jennings County and the first combat loss of a river patrol boat. These events foreshadowed a busy and dangerous year for the Game Warden sailors who boarded over 400,000 vessels and inspected them for enemy personnel and contraband. In the process, the River Patrol Force destroyed, damaged, or captured over 2,000 Viet Cong craft and killed, wounded, or captured over 1,400 of the enemy. However, the U.S. Navy suffered the loss of 39 officers and men killed, 366 wounded, and 9 missing in battle.
The Tet Offensive of 1968 fully engaged Task Force 116. Because of their firepower and mobility, the PBRs stiffened the defenses of numerous delta cities and towns that were under siege by the enemy. The river patrol boat units were key elements in the successful allied stands at My Tho, Ben Tre, Chau Doc, Tra Vinh, and Can Tho. The enemy prevailed only at Vinh Long, where the Viet Cong overran the PBR base forcing the defenders to withdraw to Garrett County. Despite this and a few other temporary setbacks, Task Force 116 reestablished firm control of the major delta rivers by mid-year and helped cut short the Viet Cong attacks on Saigon.
The river sailors also gave critical support to allied forces fighting to contain the enemy surge in I Corps. From September to October 1967, River Section 521 and Hunterdon County deployed to the river areas south of Danang and to Cau Hai Bay near Hue. PBR units operated permanently in the northern reaches of South Vietnam after 24 February 1968, when COMNAVFORV established Task Force Clearwater, under the operational control of the Commanding General III Marine Amphibious Force. The mission of the task force was to secure the Perfume River (which gave access to Hue from the sea) and the Cua Viet River. The Task Force eased supply efforts to American forces arrayed along the DMZ and holding the besieged outpost at Khe Sanh. Home for the task force headquarters was Mobile Base II, a floating barge complex stationed first at Tan My and later at Cua Viet. Because heavily armed North Vietnamese Army units were presented in this region, COMNAVFORV strengthened the 20-boat PBR task force with monitors, armored river craft, PACVs, and landing craft minesweepers. Task Force Clearwater could also call on helicopter, attack aircraft, artillery, naval gunfire, and ground troop support from other units in the I Corps region. Convoys bristling with weaponry were required to maintain the line of communication with forward combat units. The naval forces carried out equally vital minesweeping and patroling operations. During 1968, Task Force Clearwater's support was crucial to the successful defense of Khe Sanh, the recapture of Hue, and the defeat of the enemy offensive in I Corps.
Riverine Assault Force
While the object of the Game Warden force was to reduce the enemy's logistic support, that of the joint Army-Navy Mobile Riverine Force (MRF) was to locate, encircle, and destroy Communist units in battle. American military leaders patterned the MRF after the French naval assault divisions, or dinassauts, which performed well in the Indochina War from 1946 to 1954. The Americans designed a formation especially suited to the Mekong Delta, where the absence of dry land and abundance of navigable waterways made it desirable to station ground troops on board a mobile afloat base. In addition to transporting infantry and artillery, the naval component was intended to provide gunfire support for land sweeps from heavily armed and armored river craft. As finally organized, the Mobile Riverine Force consisted of an Army element, the 2d Brigade of the 9th Infantry Division, augmented in mid-1968 by the 3d Brigade, and a Navy element. The MRF was under COMUSMACV's overall direction
