Chapter VI: 
Coronado X
(January-February 1968)
Just before the 1968 lunar new year (Tet) truce, the 2d Brigade of the 9th Infantry Division launched riverine operations in the marshlands of the Mekong Delta under the code name CORONADO X. An Army-Navy mobile riverine force searched out the Viet Cong's main force and local battalions in a combination of riverine, search and destroy, patrolling, and interdiction operations. When the Viet Cong violated the temporary truce by attacking eight major cities in the delta, the mission of the mobile riverine force was refocused toward crushing the Tet offensive.
In Operation CORONADO X new equipment and techniques had to be developed for tactical mobility and fire support in the delta area, where conventional techniques were only marginally effective. The terrain was, for the most part, inundated. Swamps, rice paddies, irrigation ditches, rivers, and canals, while inhibiting the mobility of regular U.S. forces, had been used to advantage by the enemy. The mobility achieved by the riverine and airmobile forces changed this situation.
The Mekong Delta had been a target of the Viet Cong for many years. This important rice-producing area covers about one-fourth of Vietnam but contains approximately one-half of the country's population. Most of the people live in villages built along the banks of the 2,500 miles of interconnecting waterways. Since the limited network of roads often becomes impassable in the rainy season, the Viet Cong used the waterways as their chief routes for transporting men and equipment. While the helicopter allowed the allied commander to move forces with little regard to terrain, the water lines of communication were important to military operations and to the civilian economy. The Mobile Riverine Force was organized to prevent the enemy from using the waterways and to make the river system safe for the residents of the delta.
A land base had to be created in the delta area to support the Mobile Riverine Force, because there was little land available that was suitable for bases, airfields, and artillery firing positions. At a point about forty-five miles south of Saigon the base was built, using

PICTURE: USS Benewah, Afloat Base for Mobile Riverine Force, with armored troop carriers and monitors tied alongside.
with armored troop carriers and monitors tied alongside.
dredges to pump soil from the My Tho River into adjacent rice paddies. The camp, christened "Dong Tam," covered about 600 acres and provided housing and logistic facilities for the 9th Infantry Division headquarters, division support elements, and the Mobile Riverine Force. The base also had a harbor large enough to handle an LST (landing ship, tank).
In addition to the land base, mobile floating bases, consisting of naval barracks ships and watercraft, were used. The Navy elements of the Mobile Riverine Force were organized to provide an afloat base as well as combat support and combat service support to the ground forces. A river support squadron supplied barracks, repair, salvage, and supply ships. A river assault squadron contained armored troop carriers, command and communication boats, monitors (the tank of the riverine force), and assault support patrol boats. Each river assault squadron was equipped to transport and support an infantry battalion conducting combat operations in the delta.
During CORONADO X, Colonel Bert A. David, commander of the 2d Brigade, controlled the 3d Battalion, 47th Infantry; the 3d Battalion, 60th Infantry; and 3d Battalion, 34th Artillery. Captain

Robert S. Salzer, U.S. Navy, commanded the Navy elements supporting the 2d Brigade.
The Mobile Riverine Force had been conducting searches in the rice paddies of western Dinh Tuong Province when the Viet Cong launched a devastating attack against the city of My Tho. At 1730 hours on 31 January, the 2d Brigade was ordered to go to the relief of the city. When the order was received, elements of the 2d Brigade were located near Fire Support Bases ALABAMA, FLORIDA, and GEORGIA. Company B, 3d Battalion, 47th Infantry, moved to My Tho by helicopter, while other units of the 3d Battalions, 47th and 60th Infantry, boarded their armored troop carriers and moved south to the Mekong River. During night movement through narrow, uncharted, and shoal-ridden streams, the riverine force came under several attacks from small arms, automatic weapons, and rocket fire. The attacks were beaten off as barge-mounted artillery from the 3d Battalion, 34th Artillery, fired beehive rounds directly at both sides of the river. Accurate fire from the Navy monitors and other watercraft raked the banks. The two battalions and supporting artillery reached the Mekong River and joined up with the afloat base at 0220 hours on 1 February. After a short period of resupply the Army and Navy elements steamed for My Tho. Company B, 3d Battalion, 47th Infantry, which had air-assaulted into My Tho earlier, secured the beach landing sites for the battalion. The battalion beached at 1515 hours with three companies abreast and immediately began to advance north through the west side of My Tho. Automatic weapon and mortar fire from the Navy monitors and from assault support patrol boats and the barge-mounted artillery were in support. The 3d Battalion, 60th Infantry, beached to the west of the 3d Battalion, 47th Infantry, and also attacked to the north. The 47th Infantry's 3d Battalion became involved in fierce street fighting with elements of the 261st, 263d, and 514th Viet Cong Battalions. Lieutenant Colonel Ivan C. Bland moved his companies slowly and effectively, house to house and street by street. Additional artillery, air strikes, and helicopter gunships were called in to support the attacks. At the end of the day the two battalions made physical contact with the enemy and prepared night defensive positions. The 47th's 3d Battalion had killed fifty-eight Viet Cong and captured four, while losing two U.S. soldiers. The 60th's 3d Battalion killed twenty-six Viet Cong and suffered none killed in action. By 2100 hours most of the fighting had ceased, and the enemy had begun to withdraw. The next morning, 2 February, the two battalions encircled My Tho in a combined operation with Vietnamese units to sever the enemy's routes of escape. Only light resistance was encountered as the battalions located several enemy soldiers killed in the previous day's battle. The number of Viet Cong killed by the 2d Brigade rose to 106. For their heroic action in the battle of My

Tho, ten soldiers of the 2d Brigade were awarded Silver Stars on the spot by Major General George G. O'Connor, 9th Infantry Division commander.
The Mobile Riverine Force was not allowed to rest on its laurels, however, as much work had yet to be done. The Viet Cong were retreating to the northwest. Intelligence indicated that the area around Cai Lay was the likely location for the Viet Cong reorganization. At 1200 hours on 2 February, the 2d Brigade loaded back onto its armored troop carriers. Company A, 3d Battalion, 47th Infantry, was transported to Dong Tam and air-assaulted to Cai Lay. The riverine force moved west to the Ba Rai River, where it turned north toward Cai Lay. The 2d Brigade conducted search operations and blocked major rivers in order to frustrate enemy attempts to reorganize. Large food caches were discovered during search operations, but contact with the enemy was limited.
The next day, word was received that the Viet Cong were threatening to take over the city of Vinh Long, which had been hard hit. On 4 February, three Viet Cong battalions were still located south and west of the city. The 60th Infantry's 3d Battalion was moved by rivercraft to a suitable helicopter pickup zone near Cai Lay and, from there, was delivered by air assault to landing zones southwest of Vinh Long. The 3d Battalion of the 47th Infantry boarded armored troop carriers near Cai Lay and moved to beaches on the Long Ho River, southwest of Vinh Long. The battalion landed unopposed and established blocking positions oriented north toward the city. Company A of the 47th Infantry's 3d Battalion and a battery of artillery from the 3d Battalion, 34th Artillery, were airlifted from Cai Lay to secure the Vinh Long airstrip. The 3d Battalion, 47th Infantry, moved to the east of the 3d Battalion, 60th Infantry, thus completing a blockade across the southern section of Vinh Long.
In the relief of Vinh Long, the 3d Battalion, 60th Infantry, commanded by Lieutenant Colonel Hill, played the major role. The battalion came under small arms fire from a Viet Cong force shortly after landing. Companies A and E of the 3d Battalion, 60th Infantry, called in artillery and moved slowly toward the Viet Cong positions. By late afternoon, Company E had killed seven Viet Cong and captured five weapons. At 2030, however, the unit got into an all-night fight with a heavily armed Viet Cong company southeast of the city. Riverboats of the Mobile Riverine Force patrolled the waterways in the area to contain the enemy.
At dawn both battalions began search operations. The 3d Battalion, 60th Infantry, located thirty-seven dead Viet Cong. Sweep operations continued throughout the day with limited enemy contact. About 1745 hours the battalions boarded the armored troop carriers and moved by river into the Mekong Delta area and on to the afloat

base. The tired soldiers and sailors had had eight days and nights of continuous movement and combat.
After a well-deserved night's rest, the riverine force resumed its pursuit of the elusive Viet Cong. Intelligence sources indicated -that the Viet Cong were now moving south and west to the Cai Cam River. The 2d Brigade decided to deploy an "eagle float" down the river. This force was an infantry company with supporting fire mounted in armored troop carriers. In conjunction with aircraft overhead, the unit conducted a reconnaissance in force along the Cai Cam, searching for signs of the enemy. When the enemy was sighted, the eagle float moved ashore to search out the Viet Cong. After the operation, the troops quickly loaded back on the boats and got under way again. Shortly before noon the lead minesweepers of the small riverine element received automatic weapon, recoilless rifle, and rocket fire from both banks of the Cai Cam. Company B, 3d Battalion, 60th Infantry, beached immediately on the west side of the river and swept to the south. Finding no enemy troops, the company returned to the river. At midafternoon, both Companies B and E put ashore to search again for the Viet Cong. They came under enemy fire from rockets, rifle grenades, and 60-mm. mortars. Company B assaulted the Viet Cong position, killing five of the enemy, while armed helicopters, artillery, and the Navy riverboats provided fire support. As the Viet Cong retreated, Company A joined the action. To assist in trapping the enemy, the battalion commander asked Colonel David to send the 2d Brigade's ready-reaction force into the battle area. Within minutes, the men of Company B, 3d Battalion, 47th Infantry, had boarded boats and were en route to the Cai Cam River. The company arrived about 1900 hours and landed under the control of Colonel Hill. At dusk, night defensive positions were established by all units as the fighting came to a stop. The eagle float, reinforced by the Mobile Riverine Force, had killed sixty-three of the enemy, while losing four U.S. soldiers. Twenty-seven weapons were captured along with medical supplies, ammunition, and documents. On the morning of 7 February Colonel David deployed the remainder of the 3d Battalion, 47th Infantry, into the Cai Cam area. Both battalions searched the previous day's battlefield and moved southward to look for the fleeing enemy. During the day, seventeen retreating Viet Cong were killed and five weapons were captured. Both battalions loaded onto armored troop carriers and returned to the afloat base on the Mekong River.
During the period 29 January to 7 February, the Mobile Riverine Force had made three major relocations. The 2d Brigade was sent from western Dinh Tuong Province to relieve My Tho, to the north to secure Cai Lay, and finally to the southwest to protect the city of Vinh Long. After moving by boat and helicopter the soldiers of the 2d

PICTURE: Eagle Float Mobile Riverine Force beaches to search for Viet Cong
beaches to search for Viet Cong.
Brigade fought through city streets and through the muck and mire of the swamps to meet the enemy. The quick response of the riverine force and the well- co-ordinated fire from Navy rivercraft, bargemounted artillery, tactical aircraft, and helicopter gunships turned the Viet Cong offensive into a disastrous defeat. The Mobile Riverine Force was again aboard the ships of their afloat base, awaiting orders for deployment in the Mekong Delta.

The 9th Infantry Division was highly successful in adapting unit organizations, equipment, and tactics to meet the challenge of the delta's terrain and of the Viet Cong's ability to blend in with the people of the villages. "Jitterbug and seal" operations were examples of the tactical innovations aimed at reconnaissance and encirclement of elusive enemy elements. Planning for these special maneuvers started at division headquarters approximately one week before an operation. A series of targets was selected and intelligence efforts were focused on these areas. Commanders at all levels immersed themselves in the details of the intelligence process to insure a through understanding of enemy movements and patterns in their areas of operation. The day before a jitterbug and seal operation, the battalion to perform the mission was briefed on the probable targets and assigned air cavalry and airmobile support. The brigade commander would not select the specific targets until the evening before the operation so that the latest intelligence could be used. He would then choose five to seven targets for the jitterbug and seal operation. Tactical air strikes were planned in advance, and artillery was moved to cover the new targets. Orders were issued to the mission battalion, which in turn prepared two companies for the assault.
The next morning final co-ordination was completed and the mission was under way. At the first target, a helicopter with an airborne personnel detector aboard swept the area at tree-top level. Cobra gunships orbited at 500 to 700 feet, looking for fleeing Viet Cong. Scout helicopters hovered above the area and searched for bunkers, trails, or signs of movement. If the enemy's presence was suspected, riot control agents were placed on the targets, and scout helicopter pilots, wearing protective masks, hovered their aircraft near the ground, using the prop wash to spread the agent. If enemy bunkers were seen, the Cobras made firing passes to make the Viet Cong expose themselves.
Meanwhile, the first lift of a rifle company was in the air ready for action. If enemy contact was made, the battalion commander evaluated the target information and determined what size force to send into the objective area. When light enemy resistance was indicated, only five troop helicopters would land. If a large enemy force was met, the entire jitterbug force would assault the target. As the jitterbug force attacked, successive helicopter lifts encircled, or sealed, the target. All available firepower was brought to bear. As soon as the battalion's contact began to show promise, the brigade commander assumed control and alerted one of his battalions to begin sealing in the Viet Cong. The encircled enemy force was then pounded by artillery and air strikes. Canals and rivers were sealed off with concertina wire stretched from one bank to the other. Hand grenades were thrown into streams every five or ten minutes to discourage escape.

PICTURE: Barge-Mounted 105-mm. Howitzer
After several hours of bombardment, all fire was halted, and the Viet Cong were asked to surrender. Firing was resumed after the brief pause if the enemy refused.
If the enemy was located, a battalion could conduct as many as five jitterbug and seal operations a day. If no contact with the enemy developed, the battalion could search fifteen to eighteen targets a day. The 9th Infantry Division learned that when brigades performed the jitterbug and seal with skill, the ratio of enemy to friendly losses rose dramatically.
One of the problems encountered in the marshy areas of the Mekong Delta was finding suitable firing positions for artillery pieces. The 9th Infantry Division solved the problem by mounting 105-mm. howitzers on landing craft and barges that could accompany the infantry. Both direct and indirect fire could be delivered from these floating platforms. For indirect fire support, the landing craft, mechanized, was run up on a sloping bank and tied to stumps and trees. The barges mounted with artillery were secured against a steep bank in deeper water. In both cases, procedures governing the accuracy and direction of fire were the same as on land. Direct fire was particularly valuable in providing security for riverine troop movement. It

was also often used to prepare intended landing sites for the floating infantry. These variations provided the artillery with a significant extension of its capability in the delta.
Division commanders in Vietnam found the helicopter to be an effective instrument for deceiving the enemy. In an airmobile operation the commander was able to concentrate or disperse his forces quickly for tactical advantage. The same speed and flexibility was often applied in a feint to distract the enemy from the real airmobile objective or to lead him into a position favorable to the airmobile force. An enemy observer was deceived when artillery preparations and air strikes were directed on possible landing zones, followed by the false landing of a flight of helicopters, which then quickly turned and flew to the actual objective. Sometimes the aircraft would touch down in a landing zone with the soldier-passengers clearly visible. As the helicopter lifted out of the landing zone, the soldiers would lie on the floor of the helicopter giving the impression that the ground forces had unloaded.
The 9th Infantry Division used the helicopter to deceive the Viet Cong in many instances. When a jitterbug and seal operation was completed, helicopters would pick up the airmobile forces to either return them to base or move them to a new target. During several operations a false pickup was staged, leaving a portion of the force in the area to conduct ambushes or patrols. The division also used false helicopter landings to fix a Viet Cong force. To hold the Viet Cong in place, false landings were made along probable withdrawal routes to make the enemy feel that he was surrounded.
At about 0800 hours one morning, a 9th Infantry Division battalion had been conducting a reconnaissance in force when suddenly the men heard the unmistakable sound of rifle fire. Instinctively the point man hit the ground and rolled for cover, but there was only silence. Just one shot had been fired. Somewhere out there was a Viet Cong sniper. The point man surveyed the area; the only possible location for a sniper was in a wood line about 700 meters in front of him. He summoned the radio operator and reported the sniper fire to his platoon leader. A short time later the report reached the battalion commander, who immediately deployed his own sniper team to the point man's location. With its optical equipment the sniper team began a search of the tree line. Finally, the Viet Cong sniper was discovered in a tree 720 meters away. While one team member judged the wind using the M49 spotting scope, the other man fired one shot, killing the Viet Cong sniper.
The use of the sniper was not new in Vietnam, but the systematic training and employment of an aggressive, offensive sniper team -a carefully designed "weapon system"-was. A sniper was no longer just the man in the rifle squad who carried the sniper rifle; he was the

product of an established school. According to Major General Donn R. Pepke, Commanding General, 4th Infantry Division: ". . . a two week course was designed to train marksmen from each maneuver unit. Each student was armed with an accurized M14 rifle with a sniper scope mounted. This weapon was retained by the individual when he completed the course and returned to his unit." The original sniper school in Vietnam was established at the 9th Infantry Division in June 1968. The cadre consisted of one major and eight noncommissioned officers from the Army marksmanship training unit at Fort Benning, Georgia. They had extensive exp6rience in competitive shooting, and one was a practiced gunsmith familiar with the techniques for tuning the accuracy. of the M14. A training facility was constructed to accommodate thirty students. This facility included a rifle range on which targets were located up to 900 yards away.
Students for the sniper program were selected from volunteers who had qualified as expert riflemen. They were well-motivated soldiers and, in some cases, had competitive marksmanship experience. The training was so rigorous that only 50 percent of the students successfully completed the course.
The initial equipment consisted of National Match Grade M14 rifles. These rifles were glass bedded into impregnated stocks that were impervious to water. The rifles were carefully tuned to achieve a high degree of accuracy. Finally, the sniper used 7.62-mm. National Match Grade ammunition to further insure accurate firing. The selection of the M14 as the sniper rifle to be used in Vietnam was not hastily made. In early 1967 an evaluation was conducted by the U.S. Army Concept Team in Vietnam (ACTIV) to "determine the organizational, doctrinal, and materiel requirements for sniper operations." This evaluation determined that the "accurized M14 was a suitable sniper rifle for Vietnam." Several telescope sights were also tested with various degrees of success. The best sight was an adjustable power telescope that incorporated a range-finding feature. The magnification ranged from three to nine power as desired by the man firing the gun.
The most successful use of the sniper was with ambush patrols. Snipers would either accompany a platoon on an ambush or, when provided with a security element of five to eight men, establish their own ambush-sniper position. They were situated in many cases near known or suspected rice caches or tunnel entrances. Using such tactics, the sniper picked the time and place to engage the enemy, thereby maintaining the initiative. In addition, sniper teams were sometimes left behind to engage Viet Cong who were following a moving unit. The team established positions that would allow long-range observation over the route that the unit had traveled. This technique was effective because the sniper could engage targets as far away as

900 meters and because the Viet Cong tended to be lax about their cover at extreme ranges. Thus, the Viet Cong presented excellent targets. Snipers could also operate at night with the help of "pink light," an infrared searchlight that illuminated an area for a person looking through a starlight scope. This method allowed the sniper to operate anytime of the day or night.
Sniper teams were used against Viet Cong tax collectors, who came from Cambodia to collect taxes from farmers. The stay-behind sniper teams, consisting of two snipers, a radio operator, and three Popular Force soldiers, were dropped off during mechanized infantry operations near the border. The teams remained in position until dusk. According to the villagers in the area, the amount of enemy taxation was greatly reduced. Snipers were also used to prevent the enemy from re-entering areas that he commonly mined or roadblocked.
The effectiveness of the first graduates of the 9th Division's sniper school was immediately apparent. They were assigned to maneuver battalions on 7 November 1968 and made their first enemy kill on 10 November. Through 10 March 1969 the 54 snipers of the 9th Infantry Division made 135 contacts with the enemy, which resulted in 211 confirmed enemy kills. Lieutenant General Julian J. Ewell, the division commander, commented, 
"The most effective single program we had was the sniper program."
In 1968 the 9th Infantry Division tested the first Army vehicle specifically designed to meet the combat needs of military units operating in the delta: the air cushion vehicle (ACV). The limited road nets, extensive waterway systems, and seasonal flooding of land areas of the delta made an amphibious craft very desirable.
The air cushion vehicle is a modified Bell Aerosystem commercial craft. It is thirty-nine feet long and sixteen feet high. The vehicle is supported by a cushion of high-volume, low-pressure compressed air generated by a centrifugal lift fan. As the fan builds up air pressure in the cushion, the vehicle is lifted. It is almost frictionless when on the air cushion, allowing easy propulsion up to a speed of seventy-five knots. The same engine that powers the lift fan also drives a nine-foot, three-blade propeller that makes the craft speed over the delta terrain. To maintain enough air under the ACV for it to clear obstacles, flexible rubber canvas skirts are hung from the edge of the vehicle to within a fraction of an inch off the ground. The vehicle can clear solid obstacles up to 31j feet high and rice paddy dikes, with sloping sides, up to 6 feet high. The air cushion vehicle can force its way through grasses and small trees and navigate ditches and canals.
The 9th Infantry Division tested the air cushion vehicle in combat operations against the Viet Cong in the same delta region that was the scene for CORONADO X. In twenty offensive operations, the vehicle traveled over land, swamps, rivers, and the South China Sea at speeds

up to seventy knots. The craft mounted machine guns and a high velocity grenade launcher and carried ten to twelve soldiers. During the test, 43 Viet Cong were killed and 100 detained. Casualties of the, ACV units were two soldiers wounded. The craft also performed successfully in security missions and in transport of troops and cargo. The 9th Infantry Division concluded that the air cushion vehicle was suitable for combat operations in the delta and recommended that more-vehicles be deployed to Vietnam.
By the end Of CORONADO X, the Mobile Riverine Force had again proved its value by moving rapidly and efficiently through difficult terrain to relieve the cities of My Tho and Vinh Long and to pursue the enemy forces. This operation demonstrated many tactical and materiel innovations that were the result of the resourcefulness and originality of the 9th Infantry Division and supporting Navy elements. Mounting the riverine artillery on barges and platforms substantially increased the effectiveness of the force. Such fire support coupled with the mobility provided by the riverine craft, air cushion vehicles, and helicopters made the eagle float and the jitterbug and seal tactics possible. In addition, the mobility, firepower, and imaginative tactical concepts of the riverine forces seized the initiative from the enemy and vastly improved the security of the waterways for South Vietnamese citizens.

page created 15 December 2001

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