Riverine Operations
1966 - 1969
Tet Offensive of 1968 and U.S. Reaction
Shortly before the beginning of the three-day cease-fire declared by the government of South Vietnam to celebrate Tet, the lunar new year, the Mobile Riverine Force was ordered to the western portion of Dinh Tuong Province and the eastern part of Kien Phong Province to prevent the enemy from using communication routes running east and southeast through the area. There had been continuous and credible intelligence reports of enemy activity within the area, which was readily accessible to assault craft. The Mobile Riverine Force planned to establish bases along the waterways to provide fire support, as it had done during operations in the preceding November and December.
The operation began with the movement north by stages of supporting artillery batteries; as each battery moved, an infantry unit was sent ahead to secure the next fire support base. Four bases were established, three of them north along the Rach Ruong Canal from the Song My Tho to an agroville, one of the many agricultural resettlement areas established by President Diem. Three CH-47 helicopters were used to set down the artillery on the agroville site and the battery was laid and ready to fire by 1800 on 29 January 1968, the beginning of the Tet truce. The fourth base was on Highway 4, about two kilometers north from the river. The Mobile Riverine Force elements met only sporadic sniper fire on the 29th although the CH-47's were fired upon with .50-caliber machine guns.
The brigade's two battalions, in addition to defending the fire support bases, actively patrolled in the area of operations. Surveillance was aided by the radars mounted on the assault support patrol boats. At 2100 on 29 January, fifteen rounds of 82-mm. mortar fire were received at one fire support base without causing casualties or damage. No further enemy activity occurred during the remainder of the evening of 29 January and the Mobile Riverine Force dispersed to ambush positions to prevent major enemy movement.
On 25 January 1968, the senior adviser of IV Corps Tactical Zone had warned all subordinate elements in the IV Corps that
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during the impending Tet holiday cease-fire period the Viet Cong were expected to resupply and move into position for a post-Tet offensive. The warning was based on past experience and recent intelligence reports. On 29 January the senior adviser dispatched the following message:
Desire immediate dissemination of following information to all provinces without delay. There are a number of positive intelligence indicators that the enemy will deliberately violate the truce by approaching friendly installations during night of 29 January or early morning of 30 January. All provincial senior advisors will take action to insure maximum alert posture through the Tet period. 13e particularly alert for enemy deception involving use of friendly vehicles and uniforms.
About 1000 on 30 January, the Mobile Riverine Force was informed that the Military Assistance Command, Vietnam, had canceled the Tet truce because of Viet Cong attacks on cities in the three corps to the north. The force was directed to resume offensive operations "with particular attention to the defense of the Headquarters complexes, logistical installations, airfields, population centers and billets." The Mobile Riverine Force ordered increased and aggressive reconnaissance in force within the original area of operations, but the infantry was directed to operate close to the major waterways to make feasible a rapid move by water craft toward the population centers. While two companies of the 3d Battalion, 47th Infantry, remained to provide security for the fire support base, the rest of the 3d Battalion and the 3d Battalion, 60th Infantry, on 30 January conducted saturation patrolling to the east toward Cai Be. At the end of the day, forty suspects had been detained, forty bunkers destroyed, and several small caches found.
On 31 January My Tho, Ben Tre, Cai Lay, Cai Be, and Vinh Long were attacked by the Viet Cong. The Viet Cong units involved included at My Tho, the 261st, 2634, and 514th Battalions; at Vinh long, the 308th, :;06th, 857th Battalions and local forces; at Cai Be and Cai Lay, the 261st Main Force Battalion, supported by the 540th and 530dt District Companies and local forces. The Mobile Riverine Force however had not found any Viet Conk; in the populated area along the Rack Ruong. When the force moved from this area lot-al guerrillas made an effort to delay its return movement to the My Tho River. Although planning and coordination were evident in the enemy attempt to prevent movement of the Mobile Riverine Force to the scene of the major battles, the boats and their embarked battalions were able to reach the
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Mobile Riverine Base by 0220 on 1 February. After less than four hours rest, the Army and Navy elements were ordered to conduct operations in the vicinity of Cai Be. Before the landing could be executed, however, orders were changed by the senior adviser of IV Corps Tactical Zone and the river assault divisions were diverted to My Tho where allied forces were still heavily engaged. Elements of the two battalions were landed by water craft in My Tho at 1520, 1 February. The five major ships of the Mobile Riverine Base moved from Vinh Long to Dong Tam in order to be in a better position to support operations.
After landing unopposed in My Tho, Company B, 3d Battalion, 47th Infantry, secured landing sites on the southwestern edge of the city for its parent battalion and was joined by Companies A and C. As the troops began to move north into the city, they met heavy fire. With the 3d Battalion, 60th Infantry, moving on the west, both battalions advanced north through the western portion of the city, receiving small arms, automatic rifle, and rocket fire. Fighting was intense and continuous and of a kind new to the riverine battalions. The city had to be cleared slowly and systematically; pockets of enemy resistance had to be wiped out to prevent the Viet Cong from closing in behind allied troops.
While advancing through the city, Company A, 3d Battalion, 47th Infantry, met heavy fire at 1615 and Company E was ordered to reinforce. On the way, the lead elements of Company E also met intense fire and were eventually pinned down at the western edge of My Tho. At this time both maneuver battalions were involved in pitched battles and were taking casualties. The 3d Battalion, 60th Infantry, continued its movement north, advancing under heavy enemy fire, and air strikes were requested at 1740 to assist the battalion's forward elements. Troops moved in and out of doorways, from house to house, and from street to street. Artillery was employed against enemy troops who were fleeing the city. At 1955 a group of Viet Cong who had been in a previous engagement with troops of the Vietnam Army 7th Division attempted to enter the streets where Company B, 3d Battalion, was fighting, but by 2100 Company B had eliminated them.
Company A, 3d Battalion, 47th Infantry, requested a light fire team to support its point element, which had met intense resistance from small arms and rocket fire and had suffered several casualties. At 1825 the light fire team arrived and was used to relieve the pressure on Companies A and E by firing on Viet Cong positions. The team made runs directly over Company A and placed fire
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within twenty-five meters of the company's lead elements. To evacuate the wounded, a platoon leader sprinted through enemy fire, jumped into a Vietnam Array jeep parked in the street, and drove to the wounded. Ignoring the fire directed against him, lie helped the wounded men aboard the jeep and drove back to his company lines. By 2100 most of the firing had ceased and the enemy began to withdraw under cover of darkness. Throughout the night sporadic sniper fire and occasional grenade attacks were directed against the Americans and Vietnamese but no major engagements developed.
On 2 February the 2d Brigade continued to attack strongholds within the city, which was encircled by U.S. and Vietnamese units. At 0630 both U.S. battalions continued a sweep to the north in the western portion of the city, encountering only light resistance. At 0915 a Viet Cong force was engaged on the northern edge of the city. Tactical air strikes with napalm were called in and dislodged Viet Cong troops holding a guard tower near a highway bridge. The resulting damage to the bridge was repaired under fire by the Mobile Riverine Force's supporting engineer platoon. Upon completion of the sweep, the city was cleared of enemy units and the Mobile Riverine Force battalions loaded onto armored troop carriers at 1201 for redeployment to Cai Lay District in Dinh Tuong Province.
By this time, the Viet Cong offensive had lost much of its original intensity in Dinh Tuong Province and the enemy appeared to be withdrawing to the north and west. Base Area 470, where the Mobile Riverine Force had taken up positions before Tel, was thought to be a likely location for the Viet Cong to regroup. The Mobile Riverine Force therefore moved the twenty-five kilometers from My Tho to the Cai Lay area to cut off enemy escape routes from eastern Dinh Tuong Province. There were no significant engagements during the following two days as the Viet Cong apparently remained close to My Tho and did not immediately withdraw to their normal base areas.
On 4 February at the direction of the senior adviser of IV Corps Tactical Zone, the 3d Battalion, 60th Infantry, and 3d Battalion, 47th Infantry, moved to Vinh Long to relieve continued Viet Cong pressure on Vietnamese units. The two battalions were transported by helicopter and boat to positions south of Vinh Long, and together with allied elements they established a cordon around the city. The Mobile Riverine Base relocated during the day to an anchorage on the Mekong River north of Vinh Long. The 3d Bat-
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talion, 60th Infantry, completed the first airlift at 1655 with no opposition, but at 1733, on the east bank of the Rach Ca Tre Company A began to receive sniper fire. At the same time Company E was attacked with small arms and automatic weapons fire. The company returned fire and commenced movement against the Viet Cong, while artillery was used against the enemy's position. Company A meanwhile came under intense fire as it moved to its assigned sector. At 2030 Company E met a heavily armed Viet Cong company, and the fight was still in progress at 2145. As a result of this engagement, the 3d Battalion, 47th Infantry, sent
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Company C to reinforce the 3d Battalion, 60th Infantry. (Map 14)
Thus far the battalions were successfully blocking enemy movement from Vinh Long at several points. Boats of the river assault divisions conducted patrols on the Rach Long Ho and Song Co Chiem throughout the night, reporting only a few incidents. Division boats received small arms and automatic weapons fire from the west and east banks of the Rach Long Ho which was suppressed with no casualties. During the remaining hours of darkness on 4 February the 3d Battalion, 60th Infantry, continued to engage the enemy in a fight that subsided gradually. Companies A and C were low on ammunition and required resupply. At 0200 a resupply helicopter was taken under fire and downed while attempting to land, but an infantry force rescued the craft and its crew. Throughout the night the enemy probed both battalion positions, but suffered a considerable number of casualties. At dawn both battalions conducted search operations within their immediate areas and confirmed Viet Cong losses.
Operations south of Vinh Long continued on 5 February with American and Vietnamese forces attempting to clear the area by pushing south against blocks of infantrymen inserted by helicopter. Intelligence indicated there was a Viet Cong battalion in the area. Company E, 3d Battalion, 60th Infantry, conducted airmobile search operations and Company A cleared the area near the Vinh Long airfield. The 3d Battalion, 47th Infantry, operated east of the Rach Cai Cam River, encountering several small enemy forces during the afternoon. Upon completion of the sweep, the infantry was loaded aboard ATC's and by 1725 had returned to the Mobile Riverine Base, after eight clays and nights of continuous movement and combat. Company A, 3d Battalion, provided security for Vinh Long airfield and Company C, 3d Battalion, 60th Infantry, provided security for the Mobile Riverine Base and for the 3d Battalion, 34th Artillery.
On 6 February, in response to intelligence reports that the Viet Cong had succeeded in moving large forces southwest through the cordon around Vinh Long, Company B, 3d Battalion, 60th Infantry, departed the Mobile Riverine Base by boat in the early morning in an attempt to overtake the Viet Cong. The area to be searched was west of the Vinh Long airfield and south of National Highway 4. Company 13 made its first landing just south of the Highway 4 bridge over the Rach Cai Cam at 0810. Conversation with Popular Forces troops at a nearby outpost revealed that a large Viet Cong unit was in the woods and along the stream approximately 500 meters south of the bridge. Re-embarking, Com-
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pany B commenced reconnaissance along the banks of the Rach Cai Cam to the south of the bridge. At 1100 the lead element of monitors and assault support patrol boats received fire from automatic weapons, recoilless rifles, and RPG's (Russian-built antitank rockets) on both banks of the river. Company B, supported by artillery, gunships, and fire from the river craft, assaulted the west bank of the Rach Cai Cam just north of the area of the ambush and swept south. No Viet Cong were found and the company re-embarked on the ATC's and continued along the stream, landing patrols at irregular intervals.
When the Viet Cong opened fire at 1100, Company E, 3d Battalion, 60th Infantry, was dispatched by boat from the Mobile Riverine Base and arrived in the area at 1430. Company B was again landed on the west bank of the Rach Cai Cam near the 1100 firefight area, and Company E was beached at that time just opposite Company B on the east bank of the Rach Cai Cam. Almost immediately both companies came under heavy RPG, grenade, and 60-mm. mortar fire. Company B charged the Viet Cong positions in its zone, killed the enemy troops, and took four weapons, suffering two soldiers wounded. Company E had twelve wounded in the first clash and was held up while the wounded were evacuated. By 1510 the enemy had withdrawn to the southwest.
Company A, 3d Battalion, 60th Infantry, beached just south of the Regional Forces and was able to move rapidly south through the rice paddies and act as a blocking force to the west of Company B. Men of Company A observed twenty Viet Cong in the river to their west, apparently trying to escape, and called in artillery fire that caused several secondary explosions. Shortly thereafter, at 1700, all three companies received heavy automatic weapons and RPG fire from the wooded stream line in front of them and became heavily engaged.
The battalion commander, having committed all of his available infantry, requested that the brigade reserve force be committed in an attempt to encircle the Viet Cong positions. By nightfall, however, enemy forces had broken contact and the 3d Battalion, 60th Infantry, returned to the Mobile Riverine Base early on 7 February.
During the fighting from 30 January to 6 February the Mobile Riverine Force made several rapid moves over a wide area. The Mobile Riverine Force moved from the Rach Ruong Canal area of western Dinh Tuong Province to My Tho; then to Cai Lay; and, finally, to Vinh Long. The effectiveness of the Mobile Riverine Force at each city resulted in a reduction of the Viet Cong
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attacks to harrassing actions and elimination of the threat to the city. By using in combination the Mobile Riverine Base, which moved large numbers of troops and support elements between the areas, assault water craft, and supporting helicopters the Mobile Riverine Force not only moved quickly to each new area, but also arrived in strength and was able to sustain operations as needed.
From 8 through 12 February the Mobile Riverine Force deployed to the northwest of My Tho and to Gia Dinh Province near Saigon. The entire CORONADO X operation, which ended on 12 February, proved the ability of the Mobile Riverine Force to move rapidly over a large geographic area. The counteroffensive to relieve My Tho and Vinh Long highlighted the importance of having adequate air resources to use in conjunction with the ships and small assault craft of the Navy Task Force 117.
The back of the Viet Cong Tet offensive had been broken in the My Tho and Vinh Long area by the middle of February through the combined efforts of the Mobile Riverine Force and South Vietnamese armed forces. However, Viet Cong units continued to maintain pressure on Can Tho, the capital of Phong Dinh Province. The Senior Advisor, IV Corps Tactical Zone, having current operational control of the Mobile Riverine Force, decided to employ it to relieve this pressure on Can Tho. Thus CORONADO XI, the last of the CORONADO series of Mobile Riverine Force operations, was initiated. The use of the Mobile Riverine Force in the central delta was made possible by the movement of the 1st Brigade, 9th U.S. Infantry Division, from the III Corps Tactical Zone to Dinh Tuong Province. All three brigades of the 9th Division were thus placed in the delta for the first time, signaling the opportunity for the Mobile Riverine Force to move south into the Bassac River area to carry out further the original Mobile Afloat Force concept.
Before CORONADO XI, intelligence indicated that the Viet Cong, instead of withdrawing to base areas after being routed from the cities, had remained near the heavily populated areas. Later it was apparent that the enemy had left only enough men to maintain pressure on the cities so that American and Vietnamese forces would also remain nearby. Numerous intelligence reports indicated that the enemy had improved his strength throughout Phong Dinh Province, in some cases by assigning young recruits to units and sending them to battle with minimum training. This enabled the Viet Cong to display considerable force on the battlefield. The Tay Do Battalion was believed to have recruited substantial num-
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bers on the strength of its good reputation as a fighting unit. Enemy forces within Phong Dinh Province were identified as the 306th Main Force Battalion, 303d Main Force Battalion, Tay Do I and II Battalions, U Minh 10th Battalion, and Military Region III headquarters, accompanied by a security element of 200 men. The over-all mission for CORONADO XI was based on the suspected location of Viet Cong units and the Military Region III headquarters.
The mission of the Mobile Riverine Force in CORONADO XI, as developed in co-ordination with the Senior Adviser, IV Corps Tactical Zone, was to conduct riverine, air, and ground search operations in Cai Rang and Phung Hiep Districts of Phong Dinh Province, to locate and destroy Military Region III headquarters, and to conduct waterborne cordon and infantry search operations on the island of Cu Lao May in the Bassac River.
Operation CORONADO XI commenced on 12 February 1968, with the movement of the Mobile Riverine Force from Dong Tam to an anchorage in the vicinity of Can Tho. The force proceeded up the Mekong River through the waterway which connects the My Tho and Bassac Rivers, and down the Bassac to Can Tho. The force arrived shortly after 1300 on 13 February, having completed a journey of 109 miles from Dong Tam. (Map 15)
On 14 February the two infantry battalions landed from boats and conducted sweeps north along the canals immediately south of Can Tho. Army of Vietnam troops of the 9th and 21st Divisions conducted operations north of the city, sweeping to the southwest. Company A, 3d Battalion, 47th Infantry, found a cache which contained 460 B-40 rounds, 200 pounds of explosives, 89 120-mm. mortar rounds, and 500 pounds of medical supplies.
During the period 15-19 February, the Mobile Riverine Force conducted river and air operations west of Can Tho without encountering significant enemy forces. When the Can Tho airfield suffered a heavy rocket and mortar attack on 16 February, the main task of the Mobile Riverine Force was to sweep the area in the vicinity of the airfield.
On 19 February, at the request of the senior adviser of the IV Corps Tactical Zone, General Eckhardt, Task Force 117 units initiated joint waterborne patrols with units of the Vietnam Navy River Assault Group along a 13-mile stretch of the Song Can Tho to halt all sampan traffic. At 2217 a monitor was struck by B-40 rocket rounds that penetrated the 40-mm. turret. Although seven people, including a Vietnam Navy interpreter on board, were wounded, the monitor was able to suppress the enemy automatic
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weapons and small arms fire. Four of the wounded were evacuated after a rendezvous with a medical aid boat. The patrols continued throughout the night in an effort to prevent escape of Viet Cong units from the area.
On 22 February the Mobile Riverine Force and government of Vietnam forces initiated a riverine and air operation in Phung Hiep District to locate the Military Region III headquarters. The 3d Battalion, 50th Infantry, and the 3d Battalion, 47th Infantry, moved to the area of operations by means of the Kinh Saintenoy Canal. Fire support was provided by Battery C, 2d Battalion, 35th Artillery, and 3d Battalion, 34th Artillery.
To obtain the overhead clearance that the boats needed to proceed beyond the Phung Hiep Bridge, the Vietnam Army engineers raised the center span of the bridge with jacks. As the assault boats proceeded west from Phung Hiep, sporadic sniper fire from the north bank of the canal wounded four U.S. Navy men. The riverine movement beyond the bridge apparently caught the Viet Cong by surprise. When Companies B and C, 3d Battalion, 47th Infantry, beached along the Kinh Lai Hieu Canal, just northeast of Hiep Hung, the enemy was in bunkers whose fighting ports faced the rice paddies in anticipation of airmobile attacks. The
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Viet Cong ran into the open fields away from the canal where they were taken under fire by artillery and gunships and suffered heavy casualties. No additional U.S. casualties occurred.
On 23 February, the Mobile Riverine Force concluded the unsuccessful attempt to locate Military Region III headquarters and was withdrawn from the area of operations. Throughout the day there was no sight of the enemy or significant finding. The operation marked the deepest penetration yet of the Mekong Delta by U.S. forces.
On 24 February the Mobile Riverine Force conducted a waterborne cordon and search operation on the island of Cu Lao May during which both infantry battalions conducted medical civil action and dental civil action programs at enclosures where Vietnamese were detained for questioning. There was no contact with the enemy in this one-day operation. Northwest of Can Tho on 26 February, the Mobile Riverine Force met a large Viet Cong force. Company B, 3d Battalion, 60th Infantry, landed under fire that wounded many men and damaged twelve helicopters. Other elements of the Mobile Riverine Force moved to support Company B; Company E was airlifted at 1130 and landed approximately 800 meters east of Company B and Company A followed at 1405. At 1545, more than five hours after the first fire, Companies B and E were still heavily engaged and had not linked up. Linkup was effected at 1705, and because of the number of casualties sustained by Company B the company was placed under operational control of Company E. Companies A, B, and E established a night defensive position and were resupplied by 2200. The 3d Battalion, 47th Infantry, to the northwest encountered little fire throughout the day, although its scheme of maneuver was modified to allow it to provide additional support to the 3d Battalion, 60th Infantry.
Task Force 117 meanwhile had established patrols on the Song Can Tho along the southern boundary of operations to prevent escape of the enemy. About 2030 an armored troop carrier received a hit in the port bow causing an explosion. An assault support patrol boat went to the aid of the ATC and was taken under fire by automatic weapons. The enemy fire was returned and suppressed. Ten minutes later a second ATC was fired upon by a recoilless rifle. The round passed over the ATC, which immediately returned and suppressed the fire. There were no casualties among those on board in either attack. The units continued their patrols without incident until 0215 when a major action occurred as a large force of Viet Cong attempted to escape. An assault support
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patrol boat came under heavy fire from both banks and sustained several 13-40 rocket hits causing major flooding and wounding two crewmen. Other river assault craft moved into the area and suppressed the hostile fire, but one assault support patrol boat sank as it was being towed by a monitor. All crew members were rescued, but the monitor received several hits while moving to assist the disabled assault support patrol boat. During the same period, another assault support patrol boat, operating four kilometers east of the first attack, was hit by heavy rocket and automatic weapons fire. The boat captain and radio men were killed instantly and the three other crewmen were wounded but were able to beach the boat. The enemy attack lasted an hour and a half, with four assault craft involved in the battle. A light helicopter fire team helped to cut down the enemy fire.
The Viet Cong were unable to escape south across the Song Can Tho and continued to suffer casualties as the blockade was maintained successfully throughout the action. U.S. losses were moderate. During the night the Viet Cong continued harassing the Mobile Riverine Force battalions with probing attacks and sniper fire. On 27 February the area was swept again, confirming additional enemy losses and discovering caches, including five crew-served weapons, sixteen small arms, and assorted ammunition.
On 1 March, also, other elements of the Mobile Riverine Force and three Vietnam Army Ranger battalions operated approximately five kilometers southwest of Can Tho. Heavy fighting developed in the afternoon and continued into the night. The enemy slipped away before daylight and only scattered groups were found the next day.
CORONADO XI required some unusual supply operations because of the geographic location, tempo of operations, and change in control headquarters from the 9th Infantry Division to the senior adviser of IV Corps. Operations took the Mobile Riverine Force away from the normal lines of communication thus straining resupply. The severe and continuous fighting caused a heavy expenditure of ammunition and Class I and Class III supplies. The control exercised by IV Corps created a new set of logistics channels to support operations. The potential logistics problems were solved by personal liaison between the Mobile Riverine Force and Army logistics representatives located at Can Tho. Items such as C rations, fuel, and construction materials were provided by 1st Logistics Command. The IV Corps provided for evacuation of dead and wounded and responded to all Army and Navy logistics needs.
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Within the Can Tho area, most movements by Waterway and canal were accomplished without significant opposition because the enemy had no prepared fighting positions near the canals. The enemy, however, had taken excellent defensive measures against airmobile operations conducted near open rice paddies. Bunkers were well constructed, with good overhead protection against artillery and air strikes, and commanded adequate fields of fire. In one instance the Viet Cong could not engage the Mobile Riverine Force; their bunkers faced away from the waterway. The enemy attempted to escape, making themselves vulnerable to the fire of the advancing U.S. troops and supporting gunships.
The Viet Cong demonstrated their ability to employ automatic weapons fire in all battles. They characteristically used an initial heavy volume of automatic weapons fire, followed by sporadic sniper fire. Sniper fire was directed particularly at unit leaders and radio operators; snipers were well trained and extremely effective in the Can Tho area. The Viet Cong continued to fight until the late hours of the night, 2200 to 2400. They then withdrew but continued to harass U.S. positions with mortar and rocket fire.
All operations conducted in the Can Tho area made maximum use of naval and air assets, and demonstrated that logistic support planning and timely intelligence were essential. The use of air-mobility vastly influenced the course of tactical situations, especially when reserves were employed to reinforce a unit under fire or to exploit the enemy situation.
Combat operations in CORONADO XI ended on 3 March when the Mobile Riverine Force left the Can Tho area for Dong Tam. From 4 to 6 March the force assumed the division reserve role while the 3d Battalion, 47th Infantry, was replaced by the 4th Battalion, 47th Infantry, in the rotation of battalions within the brigade.
Operation TROUNG CONG DINH was initiated by the 9th Infantry Division on 7 March 1968. Its purpose was to destroy enemy forces in Dinh Tuong Province and to reduce the threat west of My Tho to Highway 4, which was being constantly menaced by the Viet Cong. The operation involved the 1st and 2d Brigades, 9th U.S. Infantry Division, the 7th Vietnam Army Division, and provincial forces. The commanding general of the 9th U.S. Infantry Division was able to employ the 2d Brigade for the first time in a continuing co-ordinated role with another division brigade. The Mobile Riverine Force conducted a series of combined riverine and airmobile operations, beginning east of My Tho. Operations
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were supported by the 3d Battalion, 34th Artillery, which established a fire support base on the north bank of the My Tho River, ten miles east of My Tho.
During initial airmobile assaults on 7 March enemy fire was light and no major firefight resulted. During the afternoon, the two battalions shifted their area of operations west-northwest of My Tho in response to intelligence reports. At 1920 the 4th Battalion, 47th Infantry, came under heavy small arms and automatic weapons fire just west of My Tho. Heavy fire continued until 2225. The following day troops met no Viet Cong in the area; at midday in response to intelligence the two battalions moved again into the area of operations of early 7 March. There were several firefights during the rest of the day. The most significant occurred at 1715 when Company B, 4th Battalion, 47th Infantry, made an assault landing by helicopter and was fired upon by a Viet Cong force from well dug in positions along the southern edge of the landing zone. Five helicopters were downed during the first landing. Throughout the evening and into the night, as other elements of the two battalions maneuvered in support of Company B, there was sporadic but heavy fighting in the area. At 0300 the fire support base was attacked by mortars that sank two artillery barges carrying four 105-mm. howitzers. The infantry continued their sweep of the previous day's battlefield without finding any Viet Cong and returned by ATC to the Mobile Riverine Base in the late afternoon.
On 10 March the Mobile Riverine Force shifted operations near Cai Lay and Long Dinh, towns of Dinh Tuong Province. Troops of the 1st and 2d Brigades, 9th Infantry Division, conducted day and night patrolling and reconnaissance in force against suspected Viet Cong locations along Highway 4 until 16 March. On 16 March the 1st Brigade terminated its participation in the TROUNG CONG DINH operation. On 18 March, boats of River Division 92 received heavy automatic weapons and rocket fire while patrolling west of Dong Tam. The rockets damaged several assault support patrol boats and one monitor. The operation continued without opposition on 19 March, and the infantry battalions returned by ATC to the Mobile Riverine Base in the vicinity of Dong Tam.
On 22 March the Mobile Riverine Base, still located in the My Tho River south of Dong Tam, was attacked at 0320 by enemy using mortars and recoilless rifles. The Benewah received two 75-mm- recoilless rifle hits that caused minor damage, and near
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misses were registered by Viet Cong mortars on an LST, the Washtenaw County.
Through the remainder of March the Mobile Riverine Force continued operations in Dinh Tuong Province with occasional light to moderate firefights. On 1 April the 3d Battalion, 60th Infantry, debarked and assumed the Dong Tam security mission and the 3d Battalion, 47th Infantry, joined the Mobile Riverine Force. Operation TROUNG CONG DINH was terminated on 2 April, after a one-battalion airmobile operation in the Ham Long District in Kien Hoa Province, just south of Dong Tam.
During TROUNG CONG DINH the Mobile Riverine Force used extensively a riverine assault reconnaissance element, a small unit first employed in December 1967 that consisted of three or four monitors and several assault support patrol boats. The riverine assault reconnaissance element led ATC convoys and employed reconnaissance by fire against likely Viet Cong ambush positions. The technique reduced casualties because of the firepower and mobility of the craft in the riverine assault reconnaissance element and the placement of ATC's carrying infantry well back in the column. Airmobility was used during TROUNG CONG DINH to increase the flexibility of the Mobile Riverine Force by providing increased intelligence, firepower, and escort coverage for convoys during troop movement.
On 4 April a significant battle was fought near the intersection of the Song Ba Lai and canals, called the Crossroads, in the Truc Giang District of Kien Hoa Province. As the boats of River Division 92 carrying the 2d Battalion, 47th Infantry, entered the Song Ba Lai they were ambushed with rockets, small arms, and automatic weapons. The battalion put into effect its counterambush plan. Company B passed through the ambush and landed unopposed just beyond the Viet Cong positions. Company E was to land just short of the ambush and the two companies were to pinch the Viet Cong between them. Instead, Company E was landed directly into the ambush, suffered heavy casualties, and was forced to withdraw. Heavy fighting with the well-protected Viet Cong continued throughout the day. The 4th Battalion, 47th Infantry, crossed from the north to assist the 3d Battalion on the south bank. Casualties among the infantry were heavy as they encountered an extensive bunker complex containing .50-caliber and other automatic weapons. The action ceased during the evening as the Viet Cong slipped away in the darkness. The two battalions continued to sweep the marshes south of the Song Ba Lai through 7 April.
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From 10 through 12 April the Mobile Riverine Force conducted successive operations near the towns of Vinh Kim and Long Dinh, and east of My Tho without major encounters. An operation in the Giong Trom and Ben Tre Districts of Kien Hoa Province on 14-15 April failed to find the enemy. At 1400 on 15 April the Mobile Riverine Base was attacked by 57- and 75-mm. recoilless rifles while at anchor. The USS Benewah received three hits; the supply LST received eight hits-all above the water line. One LCM-6 refueler was hit and later burned and sank. There were no casualties and only minor damages to the Benewah and the LST.
During the remainder of April, the Mobile Riverine Force conducted four separate operations in the Cai Lay area of Dinh Tuong Province, the western part of Kien Hoa and Dinh Tuong Provinces, and the Cam Son Base area of Dinh Tuong Province. Significant engagements were fought in three of the four operations, with the Mobile Riverine Force inflicting losses on the enemy in each encounter. Two of the operations were conducted in coordination with the 2d Vietnamese Marine Corps Battalion.
On 2 and 3 May, the Mobile Riverine Force again returned to Kien Hoa Province in response to enemy attacks on government outposts. On 5 May a survey was made of Regional Forces and Popular Forces outposts in Cai Be District to determine the extent of damage. Operations were directed from 7 through 11 May against Military Region II Viet Cong headquarters in the Giao Duc District of Dinh Tuong Province. The Mobile Riverine Force and the 2d Battalion, Vietnam Marine Corps, conducted a reconnaissance in force but encountered no large groups of enemy troops. From 14 through 16 May the Mobile Riverine Force was employed in the Mo Cay District of Kien Hoa Province and engaged the Viet Cong 516th Battalion in several firefights. The Mobile Riverine Force and elements of the 3d Brigade, 9th Infantry Division, carried out operations from 16 through 18 May, in the Than Duc District of Long An Province in co-operation with III Corps Tactical Zone Vietnam Army forces in order to reduce Viet Cong and North Vietnam Army infiltration of the Saigon area. The brigade continued operations in Long An and Dinh Tuong Province until 26 May. At that time a two-day operation was launched to reconnoiter and exploit the area of a B-52 strike in the Giong Trom District of Kien Hoa Province.
During the month of June the enemy generally avoided contact with the maneuver battalions and intensified his attacks against naval assault support craft of Task Force 117. On 5 and 6 June
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the Mobile Riverine Force conducted reconnaissance in force in the Sa Dec area. Effective use was made of the E8-a portable expendable launcher that fired riot-control cannisters-and flameboats. The period 4 through 8 June saw the Mobile Riverine Force conducting operations in the Sa Dec area and eastern Kien Phong Province. Returning to Kien Hoa Province, the force initiated operations on 10 June in the Giong Trom and Truc Giang Districts. On 16 June it moved to Can Tho, and began operations again directed by the senior adviser of IV Corps Tactical Zone to prevent a suspected Viet Cong offensive against the city. A four day operation commenced on 17 June with a major firefight in which the majority of the enemy's losses resulted from fire support by Company A, 7th Battalion, 1st Air Cavalry, in support of the maneuver battalions. Completing operations in Phong Dinh Province on 19 June, the Mobile Riverine Force moved to Dong Tam. After four days of operations near Dong Tam, it proceeded on 26 June to Long An Province where it was again employed to prevent Viet Cong and North Vietnam Army forces from moving in and out of the vicinity of Saigon. Unlike the brigade's experience in early 1968 operations in Long An Province, the enemy avoided contact with the maneuver battalions throughout the operation.
On 2 July the 2d Brigade was directed to place the 3d Battalion, 60th Infantry, under operational control of the 3d Brigade, 9th Infantry Division, which was in contact with the enemy in Dinh Tuong Province. The battalion remained under operational control of the 3d Brigade through 5 July. During that time the Mobile Riverine Force continued its operations in Long An Province, moving to Dong Tam on 5 July. On 6 July the 3d Battalion, 47th Infantry, relieved the 4th Battalion, 47th Infantry, of its security mission at Dong Tam Base. The 2d Brigade continued combat operations on 7 July in Kien Hoa Province near the canal Crossroads on the Song Ba Lai, where the 2d Brigade had previously fought one of its heaviest engagements. The 4th Battalion, 47th Infantry, entered its objective area and beached without incident. The 3d Battalion, 60th Infantry, air-landed assault troops at several spots south of the 4th Battalion beach sites. The only incidents of the day occurred when Company E of the 4th Battalion, 47th Infantry, received sporadic small arms fire and D Troop, 3d Battalion, 5th Air Cavalry, was subjected to sporadic automatic weapons fire. The limited enemy activity in the area was unlike prior experience of the Mobile Riverine Force along the Song Ba Lai.
On 10 July the Mobile Riverine Force began operations to
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locate and destroy enemy forces and equipment within the Huong My and Mo Cay Districts of Kien Hoa Province. Operations continued, through 13 July, with both battalions using boats and helicopters to search for the enemy. During the period 15 through 17 July the Mobile Riverine Force conducted riverine operations in Vinh Binh Province in co-operation with the 9th Vietnam Army Division. Completing operations in Vinh Binh Province the Mobile Riverine Force moved to Dona Tam Base on 18 July. While anchored off Dong Tam, the 2d Brigade employed the 4th Battalion, 47th Infantry, on 20 July to conduct saturation patrolling and to establish night ambushes on the south bank of the My Tho River in the Truc Giang and Ham Long Districts of Kien Hoa Province. On 21 July the 3d Battalion, 60th Infantry, was employed in a cordon and search operation in co-operation with Regional Forces and Popular Forces elements on Thoi Son Island.' Operations continued on 23 July in the Giong Trom and Truc Giang Districts of Kien Hoa Province in co-operation with the Vietnam Army. On 25 July the 2d Brigade terminated its operations in Kien Hoa Province; the next day the Mobile Riverine Force moved to Vinh Long Province.
After completing final plans and preparations for its journey the Mobile Riverine Force left its Vinh Long anchorage on 28 July and arrived in Phong Dinh Province the same day. On 30 July the force began offensive operations in co-ordination with the 5th Battalion, Vietnam Marine Corps, in the Vi Thanh area of Chuong Thien Province. To accomplish its mission, the 2d Brigade debarked from the Mobile Riverine Base and established its headquarters and tactical operations center inland in the vicinity of Vi Thanh. The Mobile Riverine Force moved into the U Minh Forest, forty-eight miles southwest of Can Tho in early August in a co-ordinated combined operation that included U.S. Army, Navy, and Air Force units and Vietnam Marine Corps and Army forces. This was the first major Allied ground operation in that area in more than a decade and another amplification of the original Mobile Riverine Force operational concept that had envisioned operations no more than twenty to thirty miles from the Mobile Riverine Base. The ten-day operation was also significant in that it substantially exceeded in scope the two- to three-day operations of the force contemplated in original plans. The operation was the first penetration by an American ground force into the U Minh Forest region and it was the deepest penetration by the Mobile Riverine Force into the Mekong Delta. The 2d Brigade established
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a land base and forward logistic support area with lines of communication extending fifty miles to the riverine base anchored near Can Tho. The operation was also destined to be the last major strike operation conducted by the Mobile Riverine Force.
By early August the Mobile Riverine Force had conducted many tactical operations in co-ordination with the other brigades of the 9th U.S. Division and with Vietnamese Army, Marine Corps, and paramilitary units. The tempo of strike operations had been maintained at a high level as the force moved from one province to another, across corps boundaries, and in response to missions originating with the commanding general of the 9th U.S. Infantry Division and with II Field Forces Vietnam through the senior adviser of the IV Corps Tactical Zone. On several occasions operations were carried on to block infiltration routes in order to cut down the threat of enemy forces present in the Capital Military District around Saigon, and near Ben Tre, Sa Dec, and Can Tho. The Mobile Riverine Force had operated in eight provinces of the Mekong Delta since early February 1968. In all operations its efforts were complemented by the co-ordinated operations of other U.S. or Vietnamese units.
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CONTENTS - Chapter 9
