Riverine Operations
1966 - 1969
Conclusions and Summary
The joint river operations conducted by the U.S. Army and Navy in South Vietnam contributed to the success of the military campaign in the Mekong Delta and added substantially to U.S. knowledge of riverine operations.
The strategic concept embodied in the plan for the Mekong Delta Mobile Afloat Force and approved by General Westmoreland in 1966 proved sound and provided a workable blueprint for a variety of projects carried out by the Mobile Riverine Force in the two years it operated. The concept recognized the importance of the Mekong Delta and its resources to the whole conflict. Although the operations planned for the river force ranged from the vicinity of Saigon south through the delta to Mui Bai Bung (Pointe de Ca Mau or Camau Point) at the southern tip of Vietnam, early priority was given to areas in southern III Corps and northern IV Corps. In executing the plan, the Mobile Riverine Force was faithful to the priority assigned to the northern delta, but never carried out fully the intent of the plan approved by General Westmoreland to extend and sustain river operations south of the Bassac River. The operations remained primarily north of the Bassac River in keeping with the area of responsibility assigned to the 9th Infantry Division in that area; the increasing role of the 2d Brigade in the division's plans; and the decrease in operational control of the force by the senior adviser of the IV Corps Tactical Zone.
Perhaps the most significant organizational aspect of the Mobile Afloat Force concept was the integration of Army and Navy units to provide a force uniquely tailored to the nature of the area of operations. Specifically, the capabilities of the two services were used to the fullest by combining tactical movement of maneuver and fire support units by land, air, and water. To this combination was added the close support of the U.S. Air Force. The Mobile Afloat Force plan stipulated that these mobile resources were not to be dissipated on independent U.S. operations but were to be used in close co-ordination with other U.S. and Free World Military Assistance Forces.
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The Mobile Riverine Force, which was the organizational implementation of the Mobile Afloat Force concept, was a fortuitous union of the Navy's River Assault Flotilla One and the Army's 2d Brigade, 9th Infantry Division. Somewhat controlled by circumstances, events,. and time, the alliance depended upon a spirit of co-operation and the initiative of the two component commanders in the Mobile Riverine Force. Guidance for the commanders was largely contained in the Mobile Afloat Force plan itself, and from the outset it was up to the commanders to make the plan work. Although many innovations were made to improve equipment and procedures, they caused little deviation from the basic Mobile Afloat Force plan. The most important innovation was the mounting of artillery on barges to provide the force with the direct support of an artillery battalion that was so urgently needed. Another innovation was the building of helicopter landing platforms on armored troop carriers and the use of a helicopter landing barge as an integral part of the forward brigade tactical command post. The adaptation by the naval commander of placing the Ammi pontons alongside the Mobile Riverine Base ships eliminated the need for cargo nets and enabled an entire company to transfer from a barracks ship to assault craft safely in less than twenty minutes.
The decision of Secretary of Defense McNamara in late 1966 to cut the requested number of self-propelled barracks ships by three eliminated berthing space for two of three infantry battalions. The Navy, however, resourcefully provided space for one of the two battalions by giving the force an APL-a barracks barge-and a larger LST of the 1152 class. The Secretary of Defense's decision could have been disastrous to the execution of the Mobile Afloat Force plan had these innovations by the Navy not been made. Even so, the brigade was forced to operate without the third maneuver battalion; the Army commander was obliged to double his efforts to secure the co-operation of Vietnam Army and other U.S. units in order to make the tactical operations of the Mobile Riverine Force successful. It can be postulated that this effort by the brigade commander to assemble a sufficient force consumed much attention and energy that could have been applied to other problems. It can also be argued that the shortage of men and the necessity to operate in conjunction with the Vietnam Army generated successes that might not otherwise have been achieved if the full maneuver force had been provided and if the force had operated less frequently in co-ordination with Vietnam Army units. Although the original Mobile Afloat Force concept provided for co-operative
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and coordinated efforts with the Vietnam Army, the shortage of troops increased the need for provincial and divisional units of the Vietnam Army throughout the various areas in which the Mobile Riverine Force operated.
It should be noted that the mobile riverine base provided for in the original plan made the force unique. When one considers that this Army and Navy force of approximately 5,000 men, capable of combat and containing within itself combat service support, could be moved from 100 to 200 kilometers in a 24-hour period and could then launch a day or night operation within 30 minutes after anchoring, its true potential is apparent. With such capabilities the force was able to carry out wide-ranging operations into previously inaccessible or remote Viet Cong territory.
The original Mobile Afloat Force concept had drawn heavily on the successful features of French riverine operations and the subsequent experience of the Vietnamese river assault groups. The Mobile Riverine Force was able also to capitalize on the knowledge of shortcomings of these earlier experiences. Both the French and the Vietnamese had used a fixed operational base on land. French units were small, rarely consisting of more than a company and five or six combat assault craft. Vietnam Army ground commanders merely used the river assault groups to transport their forces: Neither the French nor the Vietnamese had joint ground and naval forces. Both lacked the helicopter for command and control, logistic resupply, medical evacuation, and, most important, reconnaissance and troop movement. The river bases of French and Vietnam armed forces proved more vulnerable, especially during darkness, than did the afloat base of the Mobile Riverine Force. Finally, the Mobile Riverine Force, because of its mobility, strength of numbers, and Army-Navy co-operation, was capable of sustained operations along a water line of communications that permitted a concentration of force against widely separated enemy base areas. This was not true of the French or Vietnam Army riverine operations because of the small size of the forces and their dependence on a fixed base.
While the problem of command relationships did not inhibit the operations of the Mobile Riverine Force, it was a tender point in the conduct of all activities. Considering that the Army effort to develop riverine doctrine was not accepted by the Navy component commander at the outset, the Mobile Riverine Force might have been faced with insurmountable co-ordination problems, but such was not the case. Relying on the Mobile Afloat Force plan,
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each component commander had a guide to follow as to common objectives and procedures until doctrine was refined by combat experience.
No joint training for riverine operations was given in the United States because of lack of time and the wide geographic separation of Mobile Riverine Force units, but early joint training in Vietnam was planned. Fortuitously, this training commenced at the river assault squadron-battalion level under the supervision of the advance staff of River Assault Flotilla One at Vung Tau. Although the training in the Rung Sat Special Zone was under combat conditions, tactics and techniques were developed at the boat and platoon, company and river division, battalion and river assault squadron levels. During the period February-May 1967 the flotilla and brigade staffs were able to arrive at a common understanding as to organizational procedures and operational concepts. By starting at the boat and platoon level, the Mobile Riverine Force procedures were built on the needs of the lowest level units, and brigade and flotilla command and staff procedures were developed to meet these needs. With the 2d Brigade conducting tactical operations in the delta during the dry season of early 1967 and the flotilla staff co-ordinating the Rung Sat operations involving 2d Brigade battalions, both staffs gained valuable riverine experience independently. Later, as part of the transition into the Mobile Riverine Force, the advance staff of the flotilla joined the brigade staff in April at Dong Tam. This also provided a necessary step from the single battalion and river assault squadron level of operations to multi battalion, brigade and flotilla operations in late April and May of 1967.
The Mobile Riverine Force command relationships as published in a planning directive from Headquarters, Military Assistance Command, Vietnam, were a compromise to obtain Navy participation in the Mobile Riverine Force. Recognizing an ambiguous, undefined division of command responsibilities between the Army and Navy commanders, the directive compensated for this in part by instructing the chain of command of both the Army and the Navy at each level within the theater to insure co-operative effort. It also instructed the commanders at the lowest level, preferably at the Army and Navy component level of the Mobile Riverine Force, to resolve any problems that might arise. This planning directive, which incorporated the doctrine of close support and mutual co-operation and co-ordination, successfully established the tenor of what was to follow. The Navy was placed in a close support
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role that adhered closely to the Army principle of direct support. The Navy's decision in mid-1966 to make command and security of the Mobile Riverine Base an Army responsibility resolved a problem that could have become very difficult. Actually the Navy commander assumed tactical control only while the Mobile Riverine Base was being relocated. In all other instances he was cast in the role of supporting commander as long as Navy doctrine was not violated. The Army commander, acting in response to directives, operational plans, and orders from his higher headquarters, determined the plan of operations, which required the naval commander to support his objective. The major factor influencing the relationship between the Army and Navy commanders was the Navy commander's wish to operate independently of the 9th U.S. Division. This insistence provided the one element of disharmony in planning and conducting operations as an integral part of the land campaign for the delta. While it was never stated, it can be assumed that the Navy commander's position reflected the wishes of his Navy chain of command to have separate operations. In defense of the Navy's total effort, however, it can be said that the Navy commander was quick to accede to the basic concept of employing the Mobile Riverine Force in co-ordination with land operations. The activities of the Mobile Riverine Force, in fact, were directly related to the total land campaign being conducted in both III and IV Corps Tactical Zones. Joint operational orders were published and the relationship of the Army and Navy staffs in all planning and operational functions, including the establishment and manning of a joint operations center, was very close.
Perhaps the only area where a clear delineation of responsibility was not possible was at the boat and river division, river assault squadron, and battalion levels. The Navy river assault squadron organization did not parallel that of the Army battalion. Both the platoon leader and the company commander were dealing with Navy enlisted men, while the battalion commander was dealing with a lieutenant senior grade or a lieutenant commander without a comparable supporting staff equivalent to the staff of the battalion he was supporting. The Navy was thus placed in an awkward position, particularly in the event of enemy attack against an assault craft convoy. During the first six months to a year of operations, and prior to rotation of the initial Navy and Army commanders, it was normal procedure for the Navy element to answer directly to the Army officer in command during assault craft movements. The Navy craft did not use direct fire unless explicitly authorized by
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the brigade commander. As time passed and commanders rotated. however, the procedures established in the Rung Sat and in tile first six months of Mobile Riverine Force operations became vague and ambiguous since they were not committed to written joint Standing operating procedures. The difference in staff's below the brigade and river flotilla level fostered a centralization at the flotilla and brigade level in planning, control, and execution. While the Mobile Riverine Force operations gradually adhered more to the principle of decentralized planning and execution, future Mobile Riverine Force organizations should correct the disparity in the command and control organizations between echelons of the two services.
The first year of operations of the Mobile Riverine Force was highly successful because the original Mobile Afloat Force concept was carried out faithfully. The operations of the Mobile Riverine Force were wide-ranging-the force was in combat in nine provinces and the Run; Sat Special Zone. These were essentially strike operations against remote enemy base areas drat in some instances had not been penetrated in force for two or three years. From these base areas the main force Viet Cong units and the political underground had influenced the local population whose support was vital to the strategy of the Viet Cong. Because of the hold and frequent movement of the large Mobile Riverine Base from which strike operations could be launched with ease, the element of surprise so important to combat success was achieved. In most cases enemy defenses and tactics were directed toward evasion or resistance to air and land assaults. Early riverine operations often capitalized on these energy dispositions. Later, wren the enemy learned to orient his defenses toward the waterways, the 9th Division commander provided the helicopter support necessary to enable troops to maneuver rapidly front the land side against the enemy. As the first U.S. maneuver unit to conduct sustained operations in tile IV Corps Tactical 'hone, the Mobile Riverine Force developed good relationships with the commander of tile 7th Vietnam Army Division ;in([ elements of the 25th Vietnam Army Division. Co-ordinated large-scale operations were conducted in a number of remote areas, contributing to the erosion of Viet Gong strength, which before the advent of the U.S. forces in the area had been equal to that of the Vietnam Army. While the efforts of the Mobile Riverine Force were primarily concentrated against Long An and Dinh Tuong Provinces, key economic provinces for control of the delta, the force also was able to strike in Go Gong and Kien Hoa Provinces. Although only indirectly related to pacifi-
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cation, the limitations imposed on Viet Cong movement and the losses inflicted on Viet Cong units resulted in a reduction in the influence of the Viet Cong on the people in the area.
During the Tet offensive of January-February 1968, the Mobile Riverine Force was used in succession against Viet Cong forces in the populous cities of My Tho, Vinh Long, and Can Tho, which were seriously threatened. After the battles for these cities, the Mobile Riverine Force was credited with having "saved the delta" by its direct action against the enemy in these important centers before the Vietnam Army was able to rally its forces. Here again the fact that this large, concentrated force with its own base could be moved so rapidly over such great distances was the key to the Mobile Riverine Force's success against the Viet Cong in the IV Corps Tactical Zone.
During the spring of 1968 when the Mobile Riverine Force was placed under the operational control of the senior adviser of IV Corps, it again successfully penetrated remote areas. The IV Corps, however, had not the aircraft or supplies to sustain Mobile Riverine Force operations, and the force :was therefore available only intermittently to the senior adviser of the IV Corps Tactical Zone.
When 9th Division headquarters moved from Bearcat to Dong Tam in August 1.968, its mission was concentrated in Long An, Dinh Tuong, and Kien Hoa Provinces. (Map 16) With this focusing of the area of responsibility on the Mekong Delta, it can be assumed that the division commander strongly wished to integrate the Mobile Riverine Force into the divisional effort. Further, a renewed emphasis on pacification shifted the strategy away from strike operations, and as a consequence the Mobile Riverine Force largely concentrated on Kien Hoa Province. During the late summer of 1968 helicopters for troop lift were almost eliminated from the support of the force. The 9th U.S. Division decided to provide airlift chiefly for the other two operating brigades and to place almost total reliance on water movement for the 2d Brigade. This decision was a deviation from the initial operational plan of employing the Mobile Riverine Force for strikes utilizing boats and helicopters, a plan that had proved successful in the previous year's operations. Not until October of 1968 was the Mobile Riverine Force again provided with helicopters in keeping with the initial concept.
Restriction to one geographical area had limited the force in mid-1968, especially in respect to attempting surprise, and it was
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obliged to resort to other means of deception. The Viet Cong were able, however, to analyze and anticipate movements on the waterways, reportedly by using a warning system established along the banks. Because of limited and predictable water routes and a growing enemy knowledge of the Mobile Riverine Force, river ambushes became more common. When aircraft were lacking, the force was unable to retaliate except from the water. Nor was it any longer permitted to make the long moves to new areas as set forth in the Mobile Afloat Force concept. With the full use of helicopters beginning in October, the force produced results comparable with
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or superior to those of other 9th Division brigades and with the results obtained by the Mobile Riverine Force during its first year in South Vietnam.
The Mobile Riverine Force made significant contributions to the war in Vietnam. Its presence in 1967 and 1968 tipped the balance of power in the northern portion of the Mekong Delta in favor of the U.S. and South Vietnam forces. Dong Tam was developed as a division base without reducing the firm ground available to Vietnamese units in the delta and activities of the base increased the security of the important nearby city of My Tho. The Dong Tam area at one time had been under strong Viet Cong influence, and main force and local enemy units moved virtually at will until U.S. occupation of Dong Tam began in January 1967. As operations by battalions slated to join the Mobile Riverine Force continued, both the 514th and the 263d Viet Cong Battalions were brushed back from the populated area into the more remote Plain of Reeds. Even though the Viet Cong 261st Main. Force Battalion was brought as a reinforcement from Kien Hoa into Dinh Tuong Province in June of 1967, the combined operations of the Mobile Riverine Force and 7th Vietnam Army Division kept the Viet Cong from moving freely around Dong Tam. Riverine operations inflicted significant casualties on Viet Cong units and made them less effective. Highway 4, the main ground artery of the delta, which was often closed to traffic in the period 1965 through early 1967, was opened and the farm produce of the delta, both for domestic and export purposes, could reach the markets. With the completion of Dong Tam Base, the 9th Division headquarters and three brigades were finally able to move into Dinh Tuong Province and the security of the northern portion of the delta was vastly improved. When the Navy extended its efforts to the Plain of Reeds and far to the west toward the Cambodian border in late 1968 and 1969, its operations were made easier by the earlier operations of the Mobile Riverine Force during 1967 and 1968. The Navy SEA LORDS operations evolved from the concept that fielded the Mobile Riverine Force and GAME WARDEN operations.
The Mobile Riverine Force wrote a distinct chapter in U.S. military history. The joint contributions made by the Army and Navy resulted in the accumulation of a body of knowledge that has been translated into service publications setting forth joint doctrine on riverine operations. In the event of future riverine operations, the service doctrine recognizes the need for a joint task force com-
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mander to provide unity of command. Those involved in the early operations of the Mobile Riverine Force possessed no prior riverine experience and were forced to rely on historic examples, their own judgment, and related Army and Navy doctrine to build a new American force. While basic service differences did arise from time to time, those immediately responsible at all echelons from the soldier and sailor on up found reasonable solutions and carried them out effectively and harmoniously to the credit of both services.
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