Riverine Operations
1966 - 1969
Cam Son to the Rach Ruong Canal
On 11 September 1967 the Mobile Riverine Force returned to Dong Tam to prepare
for an operation that would start in the Ban Long area on 12 September, the
first operation of CORONADO V. Brigadier General Nguyen Manh Thanh, commander of
the Army of Vietnam 7th Division, furnished information that the Viet Cong 263d
Main Force Battalion had been in the Cam Son and Ban Long area during the
preceding ten to fourteen days. Although the 7th Division intelligence was known
to depend largely on reports of agents and informers, the Mobile Riverine Force
had found it highly reliable in identifying enemy base areas. In Dinh Tuong
Province particularly the force repeatedly had found the Viet Cong in regions
reported to be base areas.
Dinh
Tuong Province and Coronado V
On 12 September the Mobile Riverine Force entered the Ban Long area with three battalions. The 3d and 5th Battalions of the 60th Infantry-the 5th again released from operational control of the 3d Brigade to operate under the 2d Brigade-relied on helicopter and overland movement to get into the major east-west forested portion of the Ban Long area. The assault craft of the force were unable to navigate the waterways of the area
As the 3d Battalion, 60th Infantry, moved into the forest it found an enemy force in well-prepared positions. Assisted by artillery and close air support, the battalion advanced to the east. The Viet Cong, under the pressure of the infantry advance and supporting fire, attempted to evade to the north and northwest, exposing themselves along thinly vegetated rice paddy dikes. The 5th Battalion, 60th Infantry, northwest of the 3d Battalion, engaged a platoon of the enemy; fire from MI 13 armored personnel carriers and the battalion's mortar platoon killed or dispersed the enemy.
At approximately 1430 a provisional battalion of Dinh Tuong Province Regional Forces was sent in by helicopter northeast of
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the 3d Battalion, 60th Infantry. The provisional battalion engaged widely dispersed enemy elements that had been forced from hiding by the 3d and 5th Battalions, 60th Infantry, attacks. Mobile Riverine Forces losses were nine soldiers killed and twenty-three wounded -all from the 3d Battalion, 60th Infantry. The three battalions accounted for 134 Viet Cong killed and 39 captured. Although the main forces of the enemy had escaped on 12 September, the Mobile Riverine Force continued to search the Ban Long area until it returned to the Mobile Riverine Base on 14 September. (Map 11)
Colonel David, after consulting with General Fulton, concluded that if an operation was launched in the Cam Son area on 15 September the enemy force, tentatively identified as the 514th Local Force Battalion, might be found. The plan was to strike the area in central Cam Son where the enemy's heaviest fortifications had been identified on previous operations. To reach this area before the major enemy force could escape, Colonel David decided to withhold preparatory and reconnaissance fire until the assault craft of the Mobile Riverine Force passed a wide curve in the Rach Ba Rai referred to as "Snoopy's Nose." Helicopter flights over the area were. to be limited until the assault craft cleared Snoopy's Nose. The movement of the 5th Battalion, 60th Infantry, by ground vehicles into the area from Cai Lay was to be delayed until the 3d Battalion, 60th Infantry, and 3d Battalion, 47th Infantry, entered the Rach Ba Rai aboard ATC's. Finally, to provide a higher degree of flexibility if the enemy was found, the 2d Battalion, 60th Infantry, 3d Brigade, was designated a reserve force by the 9th Division. If required, the battalion would be employed by helicopter, staging from Dong Tam after movement from the battalion's Long An Province base.
Key elements of the maneuver were the landing of the 3d Battalion, 60th Infantry, north of an eastward bend in the Rach Ba Rai and the movement of the 5th Battalion, 60th Infantry, from the northeast. Both battalions would attack into a series of tree lines which the brigade planners believed had been used by enemy troops in the past to escape fighting.
As the 3d Battalion, 60th Infantry, moved up the Rach Ba Rai at approximately 0715 on 15 September, fire was withheld, and the assault craft moved steadily around Snoopy's Nose. By 0730 lead boats were nearing Beach White Two where a company of Lieutenant Colonel Mercer M. Doty's 3d Battalion, 60th Infantry, was to land when the boat formation came under heavy rocket, automatic, and small arms fire from both sides of the stream.
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Enemy fire was heavier from the east bank, and the organic firepower of the riverine assault craft was unleashed primarily to the right flank of the force. In the smoke and confusion the assault craft maneuvered to fire weapons or to avoid other craft temporarily out of control. One ATC proceeded north of the lead minesweepers and landed on Beach White Two with the company commander and one platoon of Company B of Colonel Doty's battalion.
During the critical fifteen to twenty minutes following initial enemy fire, the flow of information through the command and control communications net did little to reflect the situation. Colonel Doty, flying over the boat formation and observing the apparent mobility of all assault craft and the success of one ATC in arriving at Beach White Two, was convinced that his unit could continue and land at the assigned beaches. Lieutenant Commander Francis E. ("Dusty") Rhodes, Jr., commanding the assault craft supporting Colonel Doty, issued an order at 0758 for all boats to turn back and assemble in the vicinity of Beaches Red One and Two. Commander Rhodes' decision that the convoy should turn back was based on casualties to boat crews and damage to minesweepers. The standing orders of Task Force 117 required that minesweepers precede ATC's carrying troops, but he could not continue minesweeping to Beach White One. To act contrary to this procedure would constitute an action outside the "limits permitted by accepted tactical practices" of the Navy task force.
The boat captain who passed the minesweepers and landed his ATC at White Beach One was probably influenced to press on by the fact that the infantry company commander was on board. The successful movement of this one assault craft was not known to Lieutenant Commander Rhodes at the time of his decision. Colonel Doty did not waiver from his conviction that the convoy could and should continue. His S-3, Major Richard H. Sharp, aboard the command boat relayed Colonel Doty's decision to "send in the troops" to Commander Rhodes.
While the 3d Battalion, 60th Infantry, and River Assault Squadron 11 evacuated casualties, resupplied, and reorganized at the Red Beaches, the 5th Battalion, 60th Infantry, moved overland toward Beach White One from the northeast. The 3d Battalion, 47th Infantry, was commanded by Colonel Tutwiler, who had previously commanded the 4th Battalion, 47th Infantry. He held his battalion south of the congested area of Beach Red, prepared to resume movement on order.
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At approximately 1000 Colonel Doty's battalion began to move upstream, supported by artillery gunships and helicopters. The volume of fire was as great as before but the convoy landed at Beaches White One and Two. Companies B and C had few men wounded in this second run, while Company A had eighteen men wounded in one platoon. Both the assault craft and the infantry, who had joined freely in returning the enemy fire, required resupply of ammunition. Once ashore, the 3d Battalion, 60th Infantry, attacked south against stubborn enemy resistance. The 3d Battalion, 47th Infantry, landed at Beaches Red One and Two and pushed north. The 5th Battalion, 60th Infantry, moved close enough to see the 3d Battalion, 60th Infantry, by early afternoon.
To encircle the enemy south of Colonel Doty's battalion, the 2d Battalion, 60th Infantry, was placed under the operational control of the 2d Brigade and landed by helicopter south of the 5th Battalion, 60th Infantry. By dark the 3d Battalion, 60th Infantry, unable to overcome the enemy resistance, was ordered back to improve its defensive position. One Vietnam Army battalion was landed by helicopter at approximately 1600, northwest of the 3d Battalion, 60th Infantry, and moved to set up a position along the west bank of the Rach Ba Rai. The four U.S. battalions were in an irregular arc on the east side of the Rach Ba Rai. The stream was a possible enemy escape route west, although the 3d Battalion, 47th Infantry, had seized a number of sampans just north of route 212 during the late afternoon. Assault craft supporting the 3d Battalion, 47th Infantry, and 3d Battalion, 60th Infantry, were positioned to observe and place fire along the stream; however, no U.S. boats were deployed into the stream unless there were American or Vietnamese troops ashore.
During darkness air and artillery illumination was maintained over the area and artillery fire was placed within the partially encircled area on likely enemy locations. Between 0200 and 0430, small groups of enemy soldiers were observed and fired upon forward of the 2d Battalion, 60th Infantry, and later the 3d Battalion, 47th Infantry. After 0430 on 16 September no Viet Cong were sighted. On 16 September the 5th Battalion, 60th Infantry, led the sweep into the area, followed by sweeps by the two southern battalions forward of their positions. Resistance was light; most of the enemy force encountered on 15 September had been killed or had slipped away during the night.
The Navy assault craft expended, during the period 0730-1600 on 15 September, 10,273 rounds of 40-mm. ammunition, sixteen
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rounds of 81-mm., 7,445 rounds of 20-mm., 20,934 rounds of .50caliber, and 40,216 rounds of .30-caliber. The operation ended on 16 September, after four days of heavy fighting in which the Americans and Vietnamese lost 16 killed and 146 wounded and the Viet Cong lost 213.
Following the Cam Son operation, the Mobile Riverine Force moved into Kien Hoa Province. (Map 12) Although operations during the remainder of September were widely separated in Ham Long, Giong Trom, and Huong My Districts, interrogation of local civilians revealed that they had prior knowledge of the operations. In Giong Trom District local inhabitants said that a Viet Cong unit, believed to be part of the 516th Local Force Battalion, had been in the area, but had left the night before the Riverine Force arrived. This experience became characteristic of Mobile Riverine Force operations conducted in Kien Hoa Province in late 1967. Operations usually involved brushes with enemy rocket launcher and recoilless rifle teams which delayed operations but inflicted few losses. Helicopters became invaluable during movement to detect and engage small enemy teams armed with antitank weapons. These operations in Kien Hoa Province saw the first use of the long awaited assault support patrol boats.
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During the period 5-7 October, the Mobile Riverine Force terminated major operations of CORONADO V with an operation in the Ban Long area. It was conducted in close co-operation with the 7th Army of Vietnam Division and resulted in a battle with the Viet Cong 263d Main Force Battalion. The Mobile Riverine Force had 1 killed and 26 wounded, while the Vietnam Army 7th Division suffered 6 killed and 36 wounded. The Viet Cong losses totaled 163 killed.
The Mobile Riverine Force moved to Vung Tau on 10 October and CORONADO VI commenced on 11 October in the Rung Sat Special Zone. Minor engagements took place and small lots of weapons and supplies were discovered. On the night of 16 October the Mobile Riverine Force sent out forty-eight ambush patrols and twenty-two boat patrols in order to insure the security of the Long Tau shipping channel. No ships were attacked during the Mobile Riverine Force operations.
On 20 October the Mobile Riverine Force moved to the juncture of the Soi Rap and Vam Co Rivers. From this base CORONADO VII was initiated, with operations in the northern part of Can Giuoc District to secure the waterways while elections were being held in the Republic of Vietnam. Both infantry and assault craft were widely dispersed to get as many American soldiers into the area as possible. The usual search of water craft was discontinued. After the elections the commander of the 46th Vietnam Army Regiment told Colonel David that the turnout for the election had been 83 percent of the registered voters.
CORONADO VIII was conducted in co-ordination with the Royal
Thai Regiment and elements of the 3d Battalion, 5th Cavalry, on 27, 28, and 29
October in the southern Nhon Trach and the northern Rung Sat Special Zone. There
were few encounters with the enemy.
CORONADO IX began with the movement of the Mobile Riverine Base from its late October anchorage off Vung Tau to an anchorage in the My Tho River near Dong Tam. The series of operations that constituted CORONADO IX was conducted primarily north of the My Tho River and directed against the enemy bases of Dinh Tuong Province.
The Mobile Riverine Force arrived off Dong Tam 1 November 1967 and during the first days of the month concentrated on equipment maintenance and preparations for coming operations. The 3d Battalion, 60th Infantry, debarked and assumed the defense
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mission for Dong Tam Base. The battalion's waterborne replacement was the 3d Battalion, 47th Infantry, which began tactical operations in the southeastern part of the Giao Duc District in western Dinh Tuong Province at 1500 on 2 November.. During the nine-hour operation, the battalion destroyed 141 enemy bunkers and evacuated 1,100 pounds of rice and an assortment of enemy engineering and medical materials from a cache. The evacuated materials were delivered to the Dinh Tuong Province Headquarters for distribution within government programs.
On 5 and 6 November, a two-battalion operation was conducted in the Cam Son Secret Zone. Barge-mounted artillery gave support from a position on the north shore of the My Tho River. In this operation the Mobile Riverine Force destroyed 34 bunkers, captured 800 pounds of rice and 125 pounds of salt, and killed five of the enemy.
With the arrival of the 5th Battalion of the Vietnamese Marine Corps at a shore camp near My Tho on 6 November, the Mobile Riverine Force had a new and valuable asset. The 5th became the third maneuver battalion. Possessing four rifle companies and a heavy weapons company, it had a strength equal to that of the two embarked Army battalions. The Vietnamese marines brought a special esprit to the Mobile Riverine Force and fought extremely well throughout the CORONADO IX operation.
The battalion commander, Major Nam, participated fully with the advisers in the planning of Mobile Riverine Force operations. Major Nam, Colonel David, Captain Wells, and Captain Salzer, who succeeded Captain Wells on 2 December, agreed on plans and each commander approved and signed the original operation order prior to each operation. The Navy assault craft, Army artillery, and Air Force aircraft supported the Marine battalion as they did the Army battalions.
After a short time spent on training and maintenance, the Mobile Riverine Force resumed CORONADO IX on 9 November. Again the targets were the 263d and 514th Viet Cong Battalions in the Cam Son Base area. While the 3d Battalion, 47th Infantry, and the 5th Marine Battalion made beach assaults early on 9 November, the 4th Battalion, 47th Infantry, moved by ATC to the Dong Tam airstrip, and then in a series of helicopter lifts entered the area of operations. All landings were unopposed and few of the enemy were sighted.
On the second day the search for the enemy shifted to the east; troops were moved by boat and by helicopter into the Ban Long
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PORTABLE FIRING
PLATFORM WITH 105-MM. HOWITZER
and the Ap Bac base areas. Only the Marine battalion, which remained in its original area of operation, saw action, killing seven of the Viet Cong.
On 14 November, to increase security for Highway 4 and the Dong Tam Base area, a new operation began, with support from the artillery at Dong Tam. While the 3d Battalion, 47th Infantry, remained at the Mobile Riverine Base for maintenance, the other battalions were transported by boat and helicopter to the north along the Kinh Xang Canal and east of Dong Tam Base. The 5th Marine Battalion and the 4th Battalion, 47th Infantry, destroyed 63 bunkers and seized 2,000 pounds of rice and 200 pounds of salt. This operation continued through the night. Ambush patrols of platoon size were sent out along Highway 4 north of Dong Tam but saw few of the enemy.
On 16 November the Mobile Riverine Force began an operation with the 3d Brigade, 9th U.S. Division, and with elements of both the 7th and 9th Army of Vietnam Divisions along the border of Kien Phong and Dinh Tuong Provinces. The target was the
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502d Local Force Battalion and 267th Main Force Battalion, which IV Corps and II Field Force intelligence estimated were in Base Area 470. Troops of the 3d Brigade were landed by helicopter in the northern part of the area along with the 3d Battalion, 47th Infantry, which was initially under the operational control of 3d Brigade. Since Base Area 470 lacked firm ground for artillery fire support bases, and artillery positioned along Highway 4 could not cover the area, experimental artillery firing platforms were used.
One platform accommodated an M102, 105-mm. artillery piece, ammunition, and enough space for the crews to operate. The legs of the platform were adjustable to various heights and a large metal "foot," mounted on the bottom of each leg, provided support in the mud of rice paddies. A CH-47 helicopter carried the platform, artillery piece, ammunition, and crew in four lifts. One battery of 105-mm. artillery was used throughout the operation. The second night of the 3d Brigade's operations, on 17 November, the Viet Cong attacked one of the brigade's fire support bases. The attack was repulsed several hours before the Mobile Riverine Force entered the operational area off the My Tho River on the Rach Ruong Canal. In order for the Riverine Force to enter the operational area, IV Corps Vietnamese engineers, who were accompanying the assault forces early on the morning of 18 November, had to remove the center span of the bridge on the Rach Ruong Canal.
Before the bridge span was removed, a barge-mounted artillery fire support base was set up so that the artillery could fire on any enemy troops encountered by the engineers. A 155-mm. fire support base was also established on Highway 4, six kilometers east of the bridge. For better control, the Mobile Riverine Base was moved upriver from Dong Tam to an anchorage near Sa Dec. While the 5th Marine Battalion conducted riverine assaults in the southern portions of the target area, the 4th Battalion, 47th Infantry, landed troops by helicopter in the north.
Early on 18 November both battalions discovered the enemy. In the Mobile Riverine Force fighting alone, forty-five of the enemy were killed, nearly half of them by helicopter gunships, and a large medical cache was uncovered. The Mobile Riverine Force had four wounded. Total losses for all American and Vietnamese units were 26 killed and 155 wounded, while the Viet Cong suffered 178 killed and 33 taken prisoner.
Following a period at the Dong Tam anchorage for rest and maintenance, the force returned to the Cam Son Base area on 23 November. After the first air attack-a B-52 strike in the heavily
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populated Dinh Tuong Province-three battalions entered the area by riverine assault craft. Only a few of the enemy were found and eight of these were killed. Several caches were discovered.
From 27 to 30 November operations were conducted to clear the Kinh Xang Canal, which runs northwest by Dong Tam. Company D, 15th Engineer Battalion, removed all water blocks along the canal while the maneuver battalions searched the Ap Bac Base area. Five of the enemy were killed and two taken prisoner, Four major blocks were removed from the Kinh Xang Canal and sixty-two bunkers were destroyed. The opening of the upper reaches of this canal permitted the Mobile Riverine Force to use the assault craft of the Navy to attack the enemy's Ap Bac Base.
On 4 December the Mobile Riverine Base moved to Sa Dec and the 3d and 4th Battalions, 47th Infantry, with the 5th Marine Battalion, began operations to find and destroy elements of the 267th Main Force and 502d Local Force Battalions in western Dinh Tuong and eastern Kien Phong Provinces. The battle that ensued on 4-5 December proved to be one of the most severe the Mobile Riverine Force had yet experienced.
Early on 4 December the force encountered major elements of the 502d Local Force Battalion in a fortified base on the west bank of the Rach Ruong Canal. (Map 13) The enemy attacked the boats with rockets and automatic weapons and a decision was made to land the Marine battalion to the north of the enemy position. Shortly afterward the 3d Battalion, 47th Infantry, was landed south of the enemy position. Fighting was intense and Colonel David directed the 4ht Battalion, 47th Infantry, which was standing by at a pickup zone, to land west of the enemy location. In mid-afternoon of 4 December, the Vietnamese Marine Battalion made a frontal assault that overran the enemy's major bunker complex. Supporting fire from armed helicopters and assault craft contributed largely to the success of the assault. To the south the 3d Battalion, 47th Infantry, encountered stubborn resistance from scattered enemy bunkers that prevented it from linking with the Vietnamese marines.
This action demonstrated the importance of a quick decision by a waterborne force commander when the force was under fire. Major Nam decided to land immediately on what he judged to be the enemy flank. The commander of the supporting river division immediately gave the order to his boat captains, and the landings were made. Total enemy casualties for 4 and 5 December were 266 Viet Cong killed, with the Vietnamese marines accounting for the
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heaviest enemy losses. The Vietnamese marines had 40 killed and 107 wounded. Nine American soldiers were killed and 89 wounded.
The assault craft were able to land the marines with light casualties on 4 October chiefly because of a flame thrower aboard one of the armored troop carriers. A vehicle with a flame thrower had been driven aboard, and the ATC placed in the convoy to fire on targets as required. The flame thrower had not only a physical but also a psychological effect on the enemy manning bunkers south of the Marine landing site. The first successful test of a flame thrower aboard an ATC had been made on 4 October 1967.
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On 6 December the Mobile Riverine Base moved to an anchorage on the Mekong River north of Vinh Long. After three days of local operations and maintenance work during which new fire support bases were established in support of forthcoming operations, the Mobile Riverine Force undertook operations in the southern part of Cai Be District and in the western part of Dinh Tuong Province against local guerrillas and their installations. Initial landings were trade from ATC's but later in the first day of operations troops were landed by helicopter. Very few of the enemy were found.
On 14 December the Mobile Riverine Force again searched for the Viet Cong in Cain Son. The force made assaults by boat in the southern portion of the base, followed by helicopter landings by the 3d Battalion, 47th Infantry. It was not until the last clay of the operation that the enemy was discovered and in a firefight nine of the Viet Cong were killed.
On 17 December the Mobile Riverine Base moved to Dong Tam to permit the Mobile Riverine Force to land troops from the two barracks ships. By the afternoon of 18 December the brigade and one battalion had moved ashore to Dong Tatn. The USS Colleton left the area of operations to refit at Subic Bay in the Philippine Islands and the USS Benwah moved to Vung Tau in Vietnam to refit. At this time, the 3d Battalion, 60th Infantry, replaced the 4th Battalion, 47th Infantry, as part of the Mobile Riverine Force, and the 4th Battalion assumed the Doug Tam defense mission.
On 19 December a two-battalion operation was initiated in northern Cay Lay District while a third battalion operated near Dong Tam. On the night of 19 December, two companies of the 3d Battalion, 47th Infantry, were landed along the Kinh Xang Canal to set up ambushes. The other two battalions of the Mobile Riverine Force were landed by assault craft in the northern Ap Bac area. Effective artillery coverage was provided by the barge-mounted artillery and lay Battery C, 2d Battalion, 35th Artillery (155-mm. self-propelled). This operation covered most of the north central part of Dinh Tuong Province and used both helicopters and boats to land troops. Although few of the enemy were found, the maneuver battalions killed eleven Viet Cong. Navigability of the Kinh Xang Canal was extended when engineers removed a major canal obstruction. The operation was concluded late on 22 December and the Mobile Riverine Force returned to the afloat base to conduct maintenance and prepare for Christmas truce operations.
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The Mobile Riverine Force was instructed that operations should be defensive during the truce period; troops could fire on groups of enemy soldiers who "seemed to be trying to breed contact," or who were more than "platoon-size" in number. The truce ran from 1800 on 24 December through 1800 on 25 December. Prior to 1800 on the 24th, one Mobile Riverine Force battalion moved to each of the two areas in which saturation patrols were to be conducted. The 3d Battalion, 47th Infantry, moved to Long Dinh District, while to the southeast the 3d Battalion, 60th Infantry, moved into northern Kien Hoa Province. During the truce there was occasional enemy sniper and harassing fire.
The force's next operation was in Cal Lay District of Dinh Tuong Province. On 28 December the 3d Battalion, 60th Infantry, was landed by aircraft and waterborne craft in an area approximately eleven kilometers west of Dong Tam. It conducted operations directed westward toward Cai Be, with supporting fire from barge artillery batteries located to its south along the north shore of the My Tho River. Few of the enemy were seen during the operation; monitors and assault support patrol boats provided surveillance of inland waterways. On 29 December the 3d Battalion, 60th Infantry, continued operations to the west toward Cai Be, while the 4th Battalion, 47th Infantry, remained in the same area and destroyed eighty-five bunkers and captured two prisoners. During the day the 3d Battalion, 60th Infantry, found only a few of the enemy and concluded its operations in Cai Lay District.
On 30 December the 4th Battalion, 47th Infantry, was moved from Kien Hoa north and across the My Tho River to assist the 3d Battalion, 60th Infantry, in continuing operations in Cai Be and Cai Lay Districts. Although troops were shifted by boat from one place to another, the battalions could find no large groups of Viet Cong. On the following day both battalions went into positions where they stayed until the end of the New Year's truce at 0600 on 1 January 1968. In groups of platoon and company size, the battalions were dispersed to prevent the enemy from using important lines of communication during the truce period. Following the truce period the units arrived in Dong Tam on the afternoon of 2 January.
The next major mission of the Mobile Riverine Force was an operation in the eastern part of Vinh Long Province. On 7 January the battalions were landed by air and water but found no enemy until midafternoon, when a company of the 3d Battalion, 60th Infantry, came under heavy automatic weapons and small
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arms fire from an estimated two platoons. Artillery fire and air strikes were called in on the enemy, who were firing from well-prepared, concealed positions. By the end of the fight, late on 7 January, two more companies of the 3d Battalion, 60th Infantry, were engaged. Twenty-eight of the enemy were killed and three weapons were captured. The Mobile Riverine Force concluded the operation the following day, killing two more of the enemy, and reached the riverine base late that afternoon.
The next target was the 261st Main Force Battalion in the Cai Be District, western Dinh Tuong Province. On 10 January assault craft and helicopters landed the 4th Battalion, 47th Infantry, and 3d Battalion, 60th Infantry, and by mid-afternoon Company A, 3d Battalion, 60th Infantry, was in heavy combat and had sustained moderate casualties. The battalion had been set down on a "hot" landing zone. Company E was flown in to support Company A. For both companies the fighting was heavy until after dark on 10 January. The following day fighting was sporadic. Over the two days, forty-seven of the enemy were killed. American forces suffered eighteen killed and fifty wounded; most of the casualties occurred at the landing zone where the enemy was in well-prepared, excellently camouflaged positions with good fields of fire.
On 12 January an operation was conducted in conjunction with the 3d Brigade in Binh Phouc District of Long An Province. The 3d Battalion, 60th Infantry, and 4th Battalion, 47th Infantry, moved by boat along the Clio Cao Canal to assigned beaches. In landing, troops met heavy enemy rocket and automatic weapons fire but killed seven of the enemy. The rest quickly escaped and there was no further fighting during the two-day operation.
On 14 January the 2d Brigade embarked on the USS Benewah,
and was followed aboard on 21-22 January by the rest of the Mobile Riverine
Force. A cordon was thrown around the village of An Quoi, near Dong Tarn, by the
3d Battalion, 47th Infantry, which had the day before relieved the 4th
Battalion, 47th Infantry, as a Mobile Riverine Force battalion. The object of
the cordon operation was to capture or kill guerrillas, but it was unsuccessful;
the operation brought CORONADO IX to a close.
As the Mobile Riverine Force prepared for the Tet truce, it could look back over six months of unusual experiences. The force had entered the Mekong Delta in June as the first U.S. force free to conduct sustained operations against Viet Conj main force
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units whose ability was respected. Republic of Vietnam armed forces were widely dispersed, with battalions of infantry and batteries of artillery fragmented to spread a degree of security throughout populated areas along the major land and waterway lines of communication. South Vietnamese offensive operations were limited in number and duration during the hours of darkness by the need to maintain security posts at political, military, and commercial centers and on highway bridges.
The 2d Brigade did not escape the duty of maintaining security at fixed installations; one of its battalions was required at Dong Tam. The Mobile Riverine Force as a whole-a force of nearly 4,000 men-was not tied to a static security mission, but was available for wide-ranging movement.
Whether operating in southern III Corps Tactical Zone or northern IV Corps Tactical Zone, the Mobile Riverine Force added to the capabilities of the corps commanders. It provided more troops with which to expand Vietnam armed forces and Free World Military Assistance Force influence. Also it possessed significant water mobility to complement air and ground movement. The contribution of the Mobile Riverine Force on the waterways is difficult to separate from its contribution as an additional combat force even if it had not relied extensively on water mobility. The Mekong Delta in June 1967 was a place where the operations of an airmobile brigade could also have had significant impact. The Mobile Riverine Force was, however, able to attack areas such as Cam Son, the Rung Sat Special Zone, eastern Long An Province, Go Cong, and western Dinh Tuong Province where the enemy relied heavily on waterways in bases seldom violated by operations of the South Vietnamese armed forces.
These areas were lucrative targets for a force free to operate within them. They were generally remote in terms of being outside the range of established artillery positions, accessible only with great difficulty by tracked vehicles, and requiring substantial use of air or water craft for troop movement. The mobility of the barge-mounted artillery and the Mobile Riverine Base enabled the Mobile Riverine Force to give effective artillery coverage to troops and to bring other substantial combat and combat service support to operations immediately adjacent to the base area. Further, the Navy assault craft, more heavily armed and armored than the craft of the Vietnamese river assault groups and enjoying far more artillery support, were able to enter base areas into which the craft of the river assault group dared not venture. Finally, the
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Mobile Riverine Force was an unknown and, therefore, intimidating force to the Viet Cong. Intelligence estimates of June 1967 were that it would take the Viet Cong six months to obtain adequate knowledge of Mobile Riverine Force equipment, tactics, and techniques and to react with a program of mining and recoilless rifle and rocket attacks. Wide-ranging operations across the boundaries of responsibility of the major enemy organizations would gain more time before highly effective countermeasures were fielded by the enemy.
Operations were planned, therefore, so that the Mobile Riverine Force would move freely among the provinces north of the My Tho River; subsequently move south of the My Tho; eventually move into the southern Mekong Delta. In each area the force was to attack enemy main forces and local forces. By inflicting major losses on these units, the Mobile Riverine Force would take away the security provided to local guerrillas and the secret political organization by the presence of the Viet Cong main forces.
It was in the pursuance of this major mission that operations were conducted from June through December 1967. Within the widely separated-base areas, the Mobile Riverine Force inflicted losses on the 5th Nha Be Battalion and 506th Local Force Battalion of the Long An and Gia Dinh areas, on the 514th Local Force Battalion, 263d Main Force Battalion, and the Viet Cong district companies of Dinh Tuong Province, on the 502d Local Force Battalion of Kien Phong Province, and on training cadres and companies of Long An and Go Cong Provinces. These units were most frequently met in areas where water mobility permitted U.S. forces to reach fortifications and caches at the heart of the enemy base. Most enemy bunkers were chosen for defense against likely helicopter landings, and covered trails entering the base from the limited land routes; few were designed to cover an approach by water.
The Mobile Riverine Force routinely requested and planned for the use of aircraft in the conduct of operations during the last half of 1967. Often an assault helicopter company was shared during the day with the 3d Brigade, 9th Infantry Division. This arrangement, while not ideal, provided aircraft which the commanders considered an inherent part of riverine operations.
During the six-month period, Mobile Riverine Force operations departed from the original planning in respect to duration of operations and the authority for and frequency of major relocations of the Mobile Riverine Base. Plans had called for a four- to five-day
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operation, to be followed by a two- or three-day period for rest, skin care, and equipment maintenance. Beginning with Operation RIVER RAIDER 1 in the Rung Sat Special Zone, however, it was learned that foot problems caused by wetness and fungi increased rapidly after a few hours of exposure, and operations generally were limited to forty-eight hours, with a rest period of twenty-four to thirty-six hours. When it was necessary to keep troops on land for longer periods, a high percentage of foot problems occurred and rest periods of three to four days were required. Since the operations were shorter, eight instead of four operations took place each month.
A June 1967 planning directive of the Military Assistance Command, . Vietnam, stated that the Mobile Riverine Base could be relocated within the assigned tactical area of responsibility by the base commander in co-ordination with the senior Navy commander embarked. For relocation to a new area of responsibility, the commanding general of II Field Force would co-ordinate the move with the commander of Naval Forces, Vietnam, and the senior adviser of IV Corps, as appropriate, keeping Headquarters, Military Assistance Command, Vietnam, informed. This procedure was followed;, however, the base commander was able to initiate coordination for a move to a new area of operations and inform the commanding general of 11 Field Force, through the Commanding General, 9th Infantry Division. This practice was often followed; but the requirements of the planning directive issued by Headquarters, Military Assistance Command, Vietnam, were met on movements across the boundary between III and IV Corps.
The original plan to keep the Mobile Riverine Base in the same anchorage for four to six weeks was. not adhered to; more than twenty major relocations of the anchorage were made during the six months of operations-an average time at one anchorage of less than two weeks.
During the months of October and November, the Mobile Riverine Force operations in Dinh Tuong and Long An Province, where substantial numbers of the enemy had been found during previous months, met with limited success. The Viet Cong had become familiar with riverine equipment and tactics and was using small teams armed with rockets and recoilless rifles. Stationed along the waterways entering enemy base areas, the teams harassed the Mobile Riverine Force, delaying operations and inflicting casualties.
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It was clear that if the Mobile Riverine Force could find the large enemy units it could destroy them. In the 4-5 December engagement, the 502d Local Force Battalion had suffered heavy losses either because the Americans achieved surprise or because the enemy, aware of a pending attack, had decided to stand and fight. Despite this successful experience, both Colonel David and Captain Salzer noted that the enemy was becoming more difficult to find. On the eve of the Tet truce period, the Mobile Riverine Force published an order that would return the force to the scene of its last battle-western Dinh Tuong Province. The Viet Cong Tet offensive was to find the Mobile Riverine Force widely dispersed in that area and well removed from the scene of the major battles that erupted throughout the Mekong Delta on 30 January 1968. The Mobile Riverine Force would have to move quickly to the scene of the major actions during Tet.
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