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As the Mobile Riverine Force began its second year of operations in 1968, the 2d Brigade still lacked a third maneuver battalion and full use of the 3d Battalion, 34th Artillery. Successive commanders of the Brigade had reiterated the need for a third battalion to increase the flexibility of the force and to enable it to operate with area independence, but the brigades overall strength had remained basically unchanged. Two of its three battalions remained afloat with the Mobile Riverine Force, while the third infantry battalion was employed in defense of Dong Tam Base. In the absence of a third maneuver battalion the Mobile Riverine Force operated extensively in conjunction with Vietnam Amy units.

During the First half of 1968 the Navy component of the Mobile Riverine Force command to grow. In Jun a third river assault squadron was formed and in July the Navy component organized in two groups, Mobile Riverine, Group Alpha and Group Bravo By the fall of 1968, the force was scheduled to reach is full strength of 4 river assault squadrons. 184 river assault craft, 4 barracks ships. 3 repair ships, 2 barracks barges, 2 support ships, 2 resupply ships, and various other support craft.

At a riverine concept briefing on 5 January 1968, General Abrams, deputy commander of the U.S. Military Assistance Command Vietnam, had directed the U.S. Army. Vietnam, to reexamine the organization for the Army riverine battalion and the composition of the land-based brigade. The 9th Infantry Division, Headquarters, II Field Force, Vietnam and Headquarters, U.S. Army, Vietnam, concluded that the mission of the Mobile Riverine. Force could best be accomplished by a reorganization of the seven infantry battalions of die division, deleting equipment and units not essential in riverine operations. General Westmoreland approved the reorganization on 21 February 1968.

This new organization of the battalions lent itself readily to operations other than riverine, particularly airmobile operations,

without the investment in equipment and men required for continuing land-based operations. In firepower the riverine battalion, less four 81-mm. mortars, was equivalent to the standard infantry battalion even without the considerable firepower support of the Navy assault craft. By borrowing equipment, the battalion was capable of sustained operations on dry land at a saving of some 600 spaces which would be required by a standard battalion and its support elements.

The value of and continuing need for one Vietnam Marine Corps battalion to operate with the Mobile Riverine Force was also recognized. The battalion was not, however, permanently assigned to the force because Vietnam Marine Corps units were part of the Army of Vietnam general reserve and therefore subject to recall at any time. Vietnamese marines had been operating with the Mobile Riverine Force on this basis since 15 November 1967 and had contributed to successes of the force against the Viet Cong.

The CORONADO series of operations conducted from June 1967 to July 1968 had demonstrated the effectiveness of the Mobile Riverine Force in the use of waterways to deny the enemy areas where be had previously operated with relative freedom. This success led to an examination of how the riverine effort could be expanded cheaply in order to step up the tempo of operations in the Mekong Delta. A study conducted by U.S. Army, Vietnam, and Commander, Naval Forces, Vietnam, concluded that additional units of the 9th Infantry Division could be accommodated at Dona Tam without dredging. Further, with a modest addition of naval craft to the already scheduled river assault squadrons, an expanded force could support two brigades afloat and one at Dona Tam. Through judicious use of naval river craft and Army planes and helicopters the entire 9th Division could be effectively employed in the delta; the Vietnam Marine Corps and, eventually, Vietnamese river assault group units could also be drawn into operations. An organization of two Mobile Riverine Force brigades, each with three infantry battalions and supporting artillery, was considered the most desirable. The third brigade was to operate out of Dona Tam, either independently or in conjunction with the Mobile Riverine Force. This arrangement would provide flexibility, reduce reliance on land bases, demand fewer aircraft, and help sustain pressure on the Viet Cong. It would also eliminate regular river assault squadron operations out of Dona Tarn, which could develop a pattern easily detected by the enemy. The 3d Brigade with two maneuver battalions was to be sent from the Tan An

area to Dong Tam Base to facilitate its transition to the second Mobile Riverine Force. The division headquarters was transferred from Camp Martin Cox at Bearcat to its new base camp at Dong Tam on 25 July.

As of July 196$ no definite date had been established for embarking the long-awaited third infantry battalion of the 2d Brigade aboard ships of the Mobile Riverine Force. The availability of the third infantry battalion was contingent upon readjustments in 9th Infantry Division base security missions.

While general organization changes to the Mobile Riverine Force were being formulated, a major change was made in its mission. On 16 July the 2d Brigade was assigned the province of Kien Hoa as a primary area of operations, with the added mission of conducting pacification activities of a more permanent nature than those previously undertaken by the Mobile Riverine Force. The Accelerated Pacification Program guided from Headquarters, U.S. Military Assistance Command, Vietnam, prompted this assignment. After six months of operations that concentrated on the area north of the My Tho River, including Long An Province and the Rung Sat Special Zone, and after an additional six months of operations ranging more widely afield and deeper into the delta, the Mobile Riverine Force returned to concentrate on Kien Hoa. At this time Major General Harris W. Hollis, commanding the 9th Division, decided to provide the force with its third maneuver battalion and to require all three battalions to conduct airmobile and riverine operations in Kien Hoa Province. One of the battalions was based ashore in the vicinity of Ben Tre and two battalions remained afloat. The concentration on Kien Hoa Province was directed shortly after formal approval of the riverine modified tables of organization and equipment for the 2d Brigade and shortly before the arrival of the U.S. Navy craft required to lift the maneuver elements of an additional brigade.

The operational rotation of one infantry battalion from the Mobile Riverine Force to the Ben Tre base was quite different from the rotation of a battalion to Dong Tam. The May 1967 preparations of the 2d Brigade for Mobile Riverine Force operations had provided for each infantry battalion to leave at Dong Tam equipment not required when it was based afloat. Semi-permanent facilities at Dong Tam reduced the need of each battalion for organic equipment to operate a nearly independent battalion base. The first battalion sent to the Ben Tre base, therefore, required equipment that Mobile Riverine Force battalions

had not needed since before June 1967. The addition of the third infantry battalion as a land-based unit consequently brought a new organization and a logistics problem that the Mobile Riverine Force had not anticipated in its plan for employing three infantry battalions in continuing strike operations from a base entirely afloat.

Concentration by the Mobile Riverine force on Kien Hoa Province presented special considerations for operational flexibility. Previous operations in Kien Hoa had revealed the limited waterway network off the major rivers. Helicopters had proved necessary both to deploy blocking forces inland in those areas lacking navigable waterways and to assist in waterway reconnaissance. Previous operations had also demonstrated that effective anchorages for the Mobile Riverine Base to support operations in Kien Hoa were limited to four: the vicinity of Dong Tam; east of My Tho; east of Vinh Long; and east of Mocay District on the Co Chien River. Although use of each of these anchorages could facilitate operations into different districts of Kien Hoa Province, changing from one anchorage to another would not be likely to deceive the enemy.

In the past bold changes in the location of the Mobile Riverine Base had achieved surprise against Viet Cong base areas that had not been recently or frequently attacked. This major asset of the Mobile Riverine Force-the mobility of the entire force, including its logistics base-could not be fully used in the concentration of Kien Hoa Province.

Beginning in early September in Kien Hoa Province under operation HOMESTEAD, the 2d Brigade conducted operations throughout the month to find and destroy the enemy in his home territory. The enemy attacked the river craft from ambush with rockets, recoilless rifles, and small arms. According to intelligence reports, the enemy had formed special five-man teams in Kien Hoa to ambush the boats of the Mobile Riverine Force. The main ambush weapon of these teams was usually the RPG2 or RPG7 rocket launcher.

In September an additional river assault squadron and two barracks ships arrived in Vietnam to support the 3d Brigade, 9th Infantry Division. At the same time the 9th Infantry Division completed reorganization of the headquarters of 3d Brigade and one battalion into the riverine modified tables of organization and equipment in anticipation of the establishment of the second Mobile Riverine Force. By the end of 1968 three additional bat-

talions were reorganized, making a total of two brigade headquarters and seven infantry battalions configured for riverine operations.

During October Mobile Riverine Group Alpha supported pacification operations in Kien Hoa Province with the 3d and 4th Battalions, 47th Infantry, the 3d Battalion, 60th Infantry, elements of the 3d Battalion, 34th Artillery, and the 3d Battalion, Vietnam Marine Corps. Mobile Riverine Group Bravo operated with other 9th Infantry and Vietnam ground forces in Vinh Binh, Vinh Long, Long Ah, Dinh Tuong, and Phong Dinh Provinces in carrying troops and blocking Viet Cong use of waterways.

In order to make the greatest possible use of its resources during the extended period of pacification in Kien Hoa, Dinh Tuong, and Long Ah Provinces, the Mobile Riverine Force was reorganized on 15 October. Mobile Riverine Group Alpha, supporting the 9th Infantry Division pacification operations, was assigned USS Benewah, USS Askari, USS Sphinx, USS Westchester County, ztPL-26, and YLLC--4. Mobile Riverine Group Bravo, carrying out more mobile operations ranging throughout the western delta region, was assigned USS Mercer, USS Nueces, USS Vernon County, and USS Caroline County. Five river assault divisions were assigned to Mobile Riverine Group Alpha, three to Mobile Riverine Group Bravo.

By the end of October Task Force 117 had conducted liaison and training with the 21st Vietnam Army Division and had joined the 4th Vietnam Marine Corps Battalion in Navy operations known as SEA LORDS (Southeast Asia Lake Ocean River Delta Strategy). An extensive survey of the western delta canals was also made in anticipation of future operations in that area.

In November the Mobile Riverine Force continued the pattern of operations which had begun after the reorganization in October, with Mobile Riverine Group Alpha operating in the eastern delta and Mobile Riverine Group Bravo operating to the west. Of the five river assault divisions assigned to Mobile Riverine Group Alpha, River Assault Division 91 supported the 3d Vietnam Marine Corps Battalion in operations in Kien Hoa Province; River Assault Division 92 was assigned base defense duties; River Assault Division 111 supported the 3d Battalion, 34th Artillery; River Assault Division 112 operated with the 3d Battalion, 60th Infantry, in Kien Hoa Province; and River Assault Division 151 worked with the 3d Battalion, 39th Infantry, in eastern Long Ah Province Of the three river assault divisions assigned to Mobile Riverine Group Bravo, River Assault Division 121 provided for Dong Tam base

defense, River Assault Division 132 supported the SEA LORDS interdiction operations, and River Assault Division 152 supported the 4th Vietnam Marine Corps Battalion. River assault craft also supported other troop units in particular operations during the month. (Table 2)

Operations	Fire-fights	Munitions Caches Uncovered	Other Caches Uncovered	Confirmed Enemy Killed	Enemy Captured
SEARCH TURN (began 2 November 1968	200	14 (11.0 tons)	1 (1.0 tons)	219	27
TRAN HUNG DAO (began 16 November 1968)	276	3 (11.4 tons)	0	470	26
GIANT SLINGSHOT (began 6 December 1968)	1,044	244 (137.0 tons)	22 (384.9 tons)	1,910	232
BARRIER REEF (began 2 January 1969	77	1 (0.4 tons)	0	189	46

A significant incident occurred in November when USS Westchester County was mined as she lay at anchor with the other ships of Mobile Riverine Group Alpha on the My Tho River. At 0323 on 1 November, two explosions ripped separate holes on the starboard side of the LST. Three of the assault craft that were tied up alongside and two helicopters that were on board were damaged. Although the LST was not in danger of sinking, several compartments were flooded and internal blast damage was extensive. There was no damage to the ship's main engines or other machinery and she sailed to Dong Tam for emergency repairs before proceeding to a repair facility. The mining was apparently the work of enemy swimmers or sappers who penetrated, undetected, the base security forces. American casualties were 25 killed, 27 wounded, and 4 missing.

Enemy swimmers or sappers again struck the Mobile Riverine Force on the night of 15 November when the YLLC-4 (salvage lift craft, light) was mined and sunk while at anchor on the Ham Luong River. Casualties in this instance were two killed and thirteen wounded. Because damage was extensive and the location hazardous, it was determined that salvage would be uneconomical; and the craft was destroyed to eliminate it as a navigational hazard.

On 13 November 1968 the 1st Brigade replaced the 3d Brigade at Dona Taro and the 3d Brigade returned to operate in Long An Province. This deployment moved the riverine-organized 3d Brigade away from the area that the Mobile Afloat Force concept had designated for follow-up riverine operations-the area south of the My Tho River. Part of Mobile Riverine Group Alpha continued to support the 3d Brigade in Long An Province and other U.S. forces in III Corps Tactical Zone.

Riverine warfare in December again involved interdiction, escort, patrol, base area search, and pacification. Small unit Navy actions were conducted over wide areas in Kien Hoa, Kien Giang. Chuong Thien, and An Xuyen Provinces. Mobile Riverine Group Alpha operations were confined for the most part to activity in Kien Hoa Province and support of the 2d Brigade, 9th Infantry Division. Mobile Riverine Group Bravo continued to carry out a variety of special operations in the southern delta in co-ordination with units of the 2d, 3d, and 4th Battalions of the Vietnam Marine Corps.

The 2d Brigade, supported by Mobile Riverine Group Alpha, engaged in a series of operations in December designed to keep constant pressure on the Viet Con;. With frequent insertions of troops in the Hain Long, Mo Cay, and Truc Giang Districts of Kien Hoa Province, 2d Brigade ground forces continued to seek out the enemy, especially members of tile Viet Cong political organization. Of the many people detained for questioning, about 20 percent were subsequently classified as Viet Cong and the rest as innocent civilians.

Throughout .January of 1969 the Mobile Riverine Force conducted operations in the provinces of Dinli Tuong, Vinh Long, Lon- An, and Kien Hoa as the Mobile Riverine Force again moved farther afield. On 7 January two battalions were landed in the Don Nhan district of western Kien Hoa Province, an area not previously penetrated icy U.S. forces. Two platoons of enemy guerrillas were engaged by Army troops while assault craft established several water blocks to prevent tile escape of tile: guerrillas. This strategy was intended to break up tile enemy underground organization, disrupt enemy plans, demoralize enemy forces, and aid pacification. The Mobile Riverine Force used Helicopters extensively in the operation, especially ill January and February when the greatest number became available.

The activities of Mobile Riverine Group Alpha became more :and more routine as troops were transported within Kien Hoa

Province in support of tire 2d Brigade. Constant pressure was applied to enemy forces there ill support of the allied program to commit more troops and tine to tire pacification effort. Mobile Riverine Group Bravo, operating with tire 3d and 4th Battalions, .Vietnam Marine Corps, advanced into Chuong Thien, Kien Giang, Phong, Dinh, and northern Ba Xuyen Provinces.

In early January 1960 Mobile Riverine Group Alpha initiated a cordon and search operation in Thoi Son Island, in the My Tho River south of Dong Tarn. Twenty-four river assault craft of River Assault Divisions 92 and 111, two infantry battalions, eight river patrol boats, and Vietnam Navy units participated in this operation which was directed against Viet Cong guerrillas and swimmer and sapper units based on the eastern end of the island. The island people were moved temporarily to three collection points, screened by the National Police and issued new identification cards. River craft assumed blocking stations and tire island was swept by infantry units seeking Viet Cong. A total of 1,353 people voluntarily assembled at the three collection points or were apprehended in the sweep. Seventy Viet Cong were apprehended by the end of the operation on 7 ,January 1060.

On 12 January boats of River Assault Division 91 were withdrawn froth operations preliminary to the planned turnover of the river assault craft to the Vietnam Navy on 1 February. Vietnamese naval crews had undergone on-the-job training with River Assault Division 91 units since early December 1068. River Assault Squadron 13 joined Mobile Riverine Group Alpha and River Assault Division 132 was relieved by River Assault Division 92 in Operation SEA LORDS. River Assault Division 132 returned to the Mobile Riverine Base in Kien Hoa and supported the 4th Battalion, 47th Infantry. River Assault Division 131 supported the 3d Battalion, 34th Artillery; River Assault Division 112 assumed support duties for the 3d Battalion, 60th Infantry, and River Assault Division 111 assumed base defense duties.

River Assault Squadron 15 had begun reconnaissance operations in an enemy base area in southern Kien Giang Province in late December 1968 and had continued these operations into January. Eighteen river assault craft, working in co-ordination with the 2d and 3d Battalions, Vietnam Marine Corps, conducted patrols and landed troops along the Can Cao Canal. Ground fighting with enemy forces was sporadic throughout the campaign, which lasted until 7 January. Despite intelligence reports of significant enemy forces in the area, U.S. and Vietnamese troops encountered only

This same river assault squadron, with the 2d Vietnam Marine Corps Battalion, began operations along the Song Cai Tu and Song Cai Lon Rivers in Kien Giong Province on 11 January to round up enemy forces suspected of being in the region. The enemy had used the territory before for storage and for offensive operations in Chuong Tien, Kien Giang, and Phong Dinh Provinces. U.S. and Vietnamese troops were landed at a number of beaches but found only enemy ground forces of squad size or smaller. After troop landings, river assault craft established blocking stations and checked a total of 189 sampans throughout the operation, which lasted until 18 January. The enemy attacked assault craft of the riverine force eight times. Of the total of twenty-six U.S. sailors wounded, five were injured when an ATC was sunk by a water mine on the Song Cai Tu. Two sailors and one Vietnam marine died when the mined craft sank almost immediately.

On 1 February the twenty-five river assault craft of Division 91 were transferred by the U.S. Navy to the Vietnam Navy. Combining these craft with eight assault support patrol boats received directly under the military assistance program, the Vietnam Navy formed two river assault and interdiction divisions, which conducted operations in conjunction with the U.S. Navy. Coincident with the turnover, River Assault Division 91 was dissolved.

Standard infantry operations by water and air continued in February as the Mobile Riverine Force operated in several districts of Kien Hoa Province in support of the 2d Brigade. On two occasions river assault craft came under particularly heavy and well-aimed enemy fire from the river banks. On 24 February, units of River Assault Division 131 received combined rocket and automatic weapons fire from both banks of the Song Ba Lai at a position three miles northeast of Ben Tre. Six craft were hit and slightly damaged; eleven U.S. sailors were wounded. Again, on 27 February, units of River Assault Division 112 came under heavy rocket, recoilless rifle, and automatic weapons fire from both banks of the Song Ba Lai at a position four miles northeast of Ben Tye. In this attack there were twelve U.S. Navy sailors wounded and five of the river assault craft received hits causing minor damage.

Enemy swimmers with SCUBA gear were sighted in close to the USS Vernon County (LST-1161) at Mobile Riverine Base Alpha at Dong Tam on two successive days-25 and 26 February. In both cases concussion grenades were dropped into the water, and subsequent hull inspections turned up no damage.

During the same period Mobile Riverine Force elements ambushed a Viet Cong water convoy. Elements of the 3d Battalion, 60th Infantry, in night positions along the Rach An Binh, three miles southeast of Mo Cay, detected three large motorized sampans moving northward along the waterway, firing into the banks. The soldiers quickly setup an ambush and took the sampans under fire. Twenty-one of the enemy were killed and the three sampans were captured with no American casualties.

Water blockades along the Song Can Tho and Kinh Xa Mo in Phong Dinh Province, begun on 30 January by Mobile Riverine Group Bravo, continued into February. The 21st Vietnam Army Infantry Division had been conducting reconnaissance in force to prevent massing of Viet Cong in the area. The river assault craft, working in conjunction with elements of the 21st Vietnam Army Division, established a water blockade along the Song Can Tho from the Cal Range Bridge in Prong Dinh Province to a point eight miles west of Can Tho, and along the Kinh Xa Mo from Thuan Mon to the junction of the Kinh Xa Mo and Song Can Tito. One company each of the 2d Vietnam Marine Corps Battalion and the 295th Phong Dinh Regional Force were embarked as reserves. During the operation, which lasted until 3 February, over 7,000 sampans were inspected. Ground forces reported only light and sporadic fire. Enemy swimmers were seen by Mobile Riverine Group Bravo on 5, 7, and 9 February, but in each case no swimmers were captured and there was no hull damage to boats.

Operating with 160 river assault craft in March because of the transfer of the twenty-five boats to the Vietnam Navy in February, the Navy elements of the Mobile Riverine Force again ranged the delta in river assault operations in co-ordination with the U.S. Army and Vietnam armed forces. Group Alpha continued operations in Kien Hoa Province with the 2d Brigade. Attacks against river assault craft continued into March and ground units engaged in heavy firefights on several occasions. Group Bravo and the Vietnam marines conducted a successful strike into Chuong Thien Province.

A plan for again combining both task groups of the Mobile Riverine Force took effect on 4 March as the units of Task Group Alpha put in at the My Tho anchorage. The single mobile riverine base allowed for a more efficient utilization of resources and reduced the number of troops needed for base defense from two river assault divisions to one, thereby allowing the extra division to be employed in offensive operations. Tactical flexibility was also maintained should the need arise for two task groups.

During April naval units of the Mobile Riverine Force participated in diversified operations with different missions and in various areas. Reconnaissance in force, patrolling, ambushes, troop transport, inspection, fire support, blocking, escort duties, and psychological warfare were carried out by river assault craft, often in conjunction with U.S. Army or Vietnam armed forces, as they operated from northern Long An Province to the southernmost reaches of the Ca Mau peninsula. The long-term riverine assault operations in Kien Hoa Province continued as the combined Army and Navy units continued to inflict losses on the enemy.

On 22 April River Assault Division 132 was on the Cai Tu River eight and one-half miles southwest of Vi Thanh. During the firelight, a water mine exploded sixty feet off the starboard bow of a command anti control boat and caused minor flooding that was brought under control, Potential losses were averted on 24 April when a Viet ('long command-detonated mine was discovered attached to the anti-swimmer net of an APL between the bow and ponton. The homemade mine, which was estimated to weight from 150 to 175 pounds, was discovered when an antiswimmer net was being raised as the ship prepared to get under way; inspection by mine disposal experts revealed the mine with its detonator lead severed. The detonator wire was probably cut during a minesweep patrol by a base defense boat, On 29 April an assault support patrol boat was sunk on the Cai Tit River as an enemy mine was detonated beneath its stern during an operation in Chuong Thien Province.

The need for further base and boat defensive measures was apparent in the number of thwarted and successful enemy swimmer attacks against the Mobile Riverine Force, Increased emphasis was placed on use of nets, concussion grenades, and hull inspections by underwater demolition teams.

The main thrust of Mobile Riverine Force operations in May continued against the enemy in Kien Hoa Province. However, three excursions lasting up to a week each were made by detachments of six to eight river assault craft into tire Can Giuoc District of Long An Province in support of the 5th Battalion, 60th Infantry, of the 3d Brigade.

During June the U.S. Navy turned over to the Vietnam Navy sixty-four additional river assault craft valued at $18.5 million. (Table 3) Sailors of the Vietnam Navy had already trained on the job with U.S. Navy river assault craft crews with whom they had been integrated during the preceding months. River Assault

Craft	10 June	15 June	21 June	Total
ATC	12	12	11	35
ASPB	8	8	-	16
Monitor	2	3	3	8
CCB	2	1	1	4
Refueler	1	-	-	1
Total	25	24	15	64

Mobile Riverine Force activities were concentrated in Kien Hoa Province during June and consisted primarily of assault landings, troop sweeps and ambushes, and blocking, escorting, and defoliation missions, although some psychological warfare and medical civic action programs were conducted as well. Operations of limited duration also took the force into Go Cong, Long An, and Vinh Binh Provinces. The total of 554 of the enemy killed by the Mobile Riverine Force in June, although substantial, was the lowest figure since January 1969, indicating a reduced tempo of operations.

Mobile Riverine Force operations were even more limited in July. On 12 June 1969 the 9th Infantry Division had been notified of its impending departure from Vietnam. The 2d Brigade was the first to be inactivated, probably because the list and 3d Brigades had had more experience in the area just south of Saigon where there was still a need for at least one brigade. The division was inactivated in phases. The 3d Battalion, 60th Infantry, left the country in early July. The river force divisions supporting the 9th Division were used chiefly in defense of Dong Tam Base, but they also supported Vietnam Army, Regional Forces, and Popular Forces units. River Assault Flotilla One at the end of July consisted of 113 craft in five divisions, two divisions assigned to River Assault Squadron 13 and three to Squadron 15. Sixty-three of the enemy were killed in July operations.

When the departure of the 9th Infantry Division was announced, there appeared in the press considerable conjecture on the fate of the Mekong Delta. Most articles were openly pessimistic about the ability of Republic of Vietnam forces to hold onto the gains made in the Mekong Delta after two and a half years of U.S.

operations there. A feature article of 28 July 1969, "Where the Reds Are Stopped in Vietnam" in U.S. News & World Report, was guardedly optimistic, and summed up the results of riverine warfare in the delta. Viet Cong defections, it declared, had increased to 300 per month from a pre- 1969 rate of 50, and the enemy was no longer able to mass forces as he had in the past. Roads and canals that had been closed for years were now open to public use. The Vietnam government appeared to be ruling more effectively in the rural areas and refugees were moving back to their land in larger numbers.

When asked "What happens once the 9th Division leaves?" Major General Harris W. Hollis, the division commander, was quoted in a New York Times article as saying: "The mission for which this division was sent to the Mekong Delta has been largely discharged-that of dealing with the Viet Cong and the North Vietnamese until such time as Republic of Vietnam Armed Forces can take over this function. These forces, whom we have assisted, are now ready to do this."

The Navy meanwhile was well on its way toward creating a U.S. and Vietnamese force to keep the Viet Cong from using the vital rivers and canals. With the realization that no additional U.S. Army forces would be placed afloat the Navy had begun in late 1968 to search for other ways to use its great number of river craft.

As early as December 1968 the U.S. Navy, in coordination with the Vietnam Army and province forces, had begun a limited program to keep the enemy away from the rivers and canals in western Long An and Kien Tuong Provinces. In July and August 1969 as more river craft became available, the Navy initiated Operation SEA LORDS under the control of the newly formed Task Force 194 located at Can Tho. With the formal disestablishment of River Assault Flotilla One on 25 August 1969 all but one of the barracks ships were returned to the continental United States and decommissioned. The repair ships were taken over by the Naval Support Activity and dispersed throughout the delta to support SEA LORDS. The boats of two river assault squadrons were turned over to the Vietnam Navy and the remainder were absorbed by SEA LORDS.

A study conducted in preparation for SEA LORDS determined that the principal water route to exploit for the purpose of stopping

the Communist flow of supplies entering the IV Corps Tactical Area from Cambodia was the canal route linking Ha Tien on the Gulf of Thailand with Chau Doc on the upper Mekong River. This route, however, closely parallels the border and the risk of real or contrived border incidents dictated against placing a SEA LORDS barrier there until the plan had been tested in a less sensitive area. It was decided, therefore, that two parallel canals some thirty-five and forty miles southeast of the border would be used to form a double barrier and to inaugurate the SEA LORDS campaign. "Interdiction in depth had its attactiveness from an operations analysis point of view, and, at the same time, two waterways would be opened for friendly traffic. In conjunction with this barrier, river patrols would be strengthened from Long Xuyen through the Vain Nao Crossover to the Mekong."

The second objective of SEA LORDS-control of vital trans-delta inland waterways-would be accomplished by the removal of obstructions to navigation in the Clio Gao Canal linking the Vain Co and My Tho Rivers; by strike operations along the Mang ThitNicolai Canal, which joins the Co Chien and Bassac Rivers; and by reopening of the Bassac-Bac Lieu rice route in the lower delta. Penetration of rivers in the Cau Mau peninsula, the third objective, actually began before formal proposals were made to the senior adviser of IV Corps Tactical Zone, Major General George S. Eckhardt. A patrol boat incursion of the Cua Long River on 18 October 1968 is usually considered the first of the SEA LORDS operations, although a few earlier such operations were conducted by MARKET TIME.

General Eckhardt endorsed the Navy's proposals, and organization for SEA LORDS proceeded rapidly. Captain Robert S. Salzer, U.S. Navy, previously commander of the Navy component of the Mobile Riverine Force, was designated First Sea Lord and assigned a staff of nine officers and six. enlisted men at General Eckhardt's headquarters in Can Tho. The Commander of Naval Forces, Vietnam, was given the task force number 194. Captain Salzer became commander of Task Group 194.0 and exercised operational control commencing 15 October 1968 of three other task groups: 194.5, Coastal Raiding and Blocking Group; 194.6, Riverine Raiding and Blocking Group; and 194.7, Riverine Strike Group. He was directed to designate one of the three task force commanders to command each specific SEA LORDS operation, with the commander of Task Force 115 usually expected to direct SEA LORDS invasions from the sea and the commander of Task

On 2 November the first of the barrier campaigns, later given the name SEARCH TURN, was launched. Heavy craft of the Mobile Riverine Force and supporting ground troops succeeded in securing the waterways in a five-day operation that resulted in twenty-one Viet Cong killed and the capture of sizable quantities of arms and ammunition. A permanent naval patrol was then established, its main purpose to keep secure the western ends of the barrier and the network of perpendicular canals running north from Rach Gia to Ha Tien. According to intelligence reports, the principal Communist messengers passed through this territory.

While the operation was in progress other SEA LORDS forces were employed in clearing the Clio Gao Canal, which was open to navigation on 6 November. Later in the month Tan Dinh and Dung Island in the Bassac River were sealed off by a naval blockade while ground forces conducted sweep operations. MARKET TIME boats moved into areas in the Ca Mau peninsula that had long been considered exclusively the domain of the Viet Cong. The second of the interdiction barriers was established on 16 November 1968, and a third on 6 December 1968. Given the code name GIANT SLINGSHOT, this last campaign achieved the most dramatic and telling effects on enemy infiltration of all the interdiction barriers.

Thirty miles west of Saigon a peculiarly drawn border thrusts the Cambodian "Parrot's Beak" deep into Vietnam's III Corps area. The Parrot's Beak had long been known as a Communist base from which supplies moved across the border, and well-documented infiltration routes had been traced. These entered South Vietnam between the Vam Co Tay and Vam Co Dong Rivers; one turned south into the delta, the other east to supply the Viet Cong in the countryside surrounding the capital. The two rivers flow on either side of the Parrot's Beak on converging courses to the southeast. They appear to form a slingshot into which the Parrot's Beak neatly fits, hence the code name GIANT SLINGSHOT. For ground support in the GIANT SLINGSHOT operation, Rear Admiral William H. House, who had assumed the post of First Sea Lord upon Captain Salzer's departure, called on the commanding general of II Field Force, Vietnam, Lieutenant General Frederick C. Weyand, and got his endorsement and promise of help.

Because of the distances involved and because it was impossible to bring large ships up river beyond the low bridges at Tan An and Ben Luc, a new basing and support scheme was devised for GIANT

SLINGSHOT. An advance tactical support base vas designed, consisting of three or more 30X90-foot Ammi barges on which berthing and messing facilities, storerooms, and a tactical operations center could be constructed and which would contain water purification equipment, generators, and other assorted machinery.

Advance tactical support bases were established at Tuyen Nlion and Moc Hoa on the Vam Co Tay and at Tra Cu and Hiep Hoa on the Vain Co Dona. The site at Hiep Hoa was later abandoned in favor of one at Go Dan Ha and in July 1969 an additional base was placed at Ben Keo near the important city of Tay Ninh. The USS Askari and the berthing and messing barge for underwater repair crews were at Tan An, awaiting the arrival of Mobile Base II, a sophisticated four-Ammi complex, specially constructed in the United States with improved berthing and messing facilities and equipped to make extensive boat repairs. The USS Harnett County provided. support at Ben Luc for the patrol boats until the completion of a shore support base there.

From its very inception, GIANT SLINGSHOT was characterized by frequent, heavy clashes between patrol boats and enemy forces intent on maintaining the lines of communication to their Cambodian storehouse. Extremely large quantities of arms, munitions, and supplies were uncovered in caches buried along the river banks, proving beyond doubt that vital enemy infiltration lines had been cut.

The fourth and last of the interdiction barriers in the Mekong Delta was established on 2 January 1969 when naval patrols began operations on the La Grange-Ong Lon Canal from Tuyen Nlion on the Vam Co Tay River to An Long on the Mekong. Called BARRIER REEF, this operation joined GIANT SLINGSHOT In the east with the two interdiction barriers in the west, SEARCH TURN and TRAN HUNG DAO. The northern ring was then complete; the enemy was no longer free to move men and supplies with impunity from Cambodia into III and IV Corps areas. A naval "tariff" had been imposed on those shipments, measurable in terms of men and supplies captured or destroyed, but the supplies and men that were prevented from getting through cannot be calculated.

Once the barriers were in place, the boats were used to counter enemy pressures and probes. With relatively little disruption to existing organization and logistics, boats were shifted rapidly from one area of operations to another. For example in Operation DOUBLE SHIFT in July 1969, 105 U.S. Navy and Vietnamese Navy boats were quickly concentrated on the waters of the Vam Co Dong north of Go Dau Ha in response to serious enemy threats

to the city of Tay Ninh. This sudden and impressive display of naval power, directed by the commander on the scene, Lieutenant Commander Thomas K. Anderson, U.S. Navy, was credited by the commander of 11 Field Force, Lieutenant General Julian J. Ewell, with leaving prevented the enemy attack on Tay Ninh from the southwest.

On two separate occasions the mobility of the boats was increased when giant Army skycrane helicopters were used to lift some of theta into new areas of operations. In May 1969 six river patrol boats were skyhooked to the upper Saigon River, and in .June six more were lifted to the otherwise inaccessible Cal Cai Canal. Both operations achieved tactical surprise.

As each operation progressed, concerted efforts were made to integrate units of the growing Vietnamese Navy. The military desirability and political necessity to "Vietnamize" the naval war were evident long in advance of SEA LORDS planning. It seemed obvious that the Vietnamese Navy's hope of relieving the U.S. Navy of its operational responsibilities in the war as soon as possible would he considerably enhanced by success of SEA LORDS. SEA LORDS was a remarkable organization which came to mean unity of command and rapid response to changing tactical situations. Relatively junior officers and men were often placed in positions of extraordinary responsibility. Tactics and techniques were developed and tested in the heat of combat, and at times even borrowed from the enemy. improved upon, and used to defeat him. The waterborne guard post, for instance, was a refinement of the favorite enemy tactic of ambush. Using silent boats and night observation devices, the U.S. and Vietnamese boats stalked the would-be Viet Cong ambusher and trapped him. Imagination and leadership provided the plan and a dedicated collection of sailors, soldiers, and airmen made it work.

In addition to use in SEA LORDS, the United States rivercraft turned over to the Vietnam Navy at Can Tho were used to support Vietnam Marine Corps and Vietnam Army units in the central delta. Operations were conducted in the style of the Mobile Riverine Force, but greater emphasis was placed on leaving security forces in areas that lead been cleared so that the Vietnam government could continue to control them. The Array-Navy Mobile Riverine Force, which had operated in the Mekong Delta since February 1967, was disestablished on 25 August 1969 and River Flotilla One and 2d Brigade, 9th Infantry Division, were inactivated. The experience of these units was inherited by SEA LORDS and ultimately by the Vietnam Army and Navy.