The Brown Water Navy in Viet Nam
From the commencement of the Viet Nam war the tactical and economic standing of the South’s extensive inland waterways dictated that the U.S. Navy should lead the allied forces during the conflict.
Intertwined with approximately 3,000 nautical miles of rivers, canals, and streams, the lush Mekong Delta region located south of Saigon had the largest segment of the South Vietnam population and so it constituted the country’s “rice bowl” that produced the majority of the country’s crop of rice.
Northward along the coast to the DMZ large rivers stretched inland past vital population centers such as the old imperial capital of Hue that originally rose to prominence as the capital of the Nguyễn lords, a feudal dynasty that dominated much of southern Vietnam from the 17th to the 19th century. Since the country’s road and rail systems were rudimentary it was the waterways that permitted ready access to the region’s most significant resources. So, whoever could control the rivers and canals acquired the tactical advantage to control the heart of South Vietnam.
Therefore, USN leaders were resolute to have allied forces seize control of the waterways and so they established a plan to initiate the River Patrol Force and designated it Task Force 116 on 18 December 1965 to meet their objective. When the operation took effect the Navy divided Task Force 116 into two separate task groups and assigned them to specific regions within the Delta with Task Group 116.1, a force of 80 PBRs, assigned to patrol the heart of the Mekong Delta and operate out of river’s edge bases in My Tho, Vinh Long, Can Tho, Sa Dec, and Long Xuyen. And, the second division, Task Group 116.2, which was roughly half the size designated to protect the Rung Sat Special Zone using base areas in Nha Be and Cat Lo.
Consequently, in March 1966 the Navy commenced procurement of river patrol boats (PBRs) built in the United States and then trained their crews at the USN Coronado and Mare Island, California training center, and then deployed the units to Southeast Asia to begin Operation “Game Warden.” The River Patrol Force was also designated River Patrol Squadron 5 for administrative and supply purposes and by August 1968 the force consisted of five river divisions with each commanding two 10-boat squadrons that operated from combat bases along the key rivers, or from Navy ships stationed in the rivers that served as floating base facilities for each PBR section and a helicopter detachment.
Operation Game Warden was a joint operation of the United States and South Vietnamese navies in order to deny Viet Cong access to resources in the Mekong Delta. Game Warden and its counterpart Operation Market Time are considered to be two of the most successful U.S. Naval actions during the Vietnam War.
Patrol Boat River or PBR, is the United States Navy designation the small rigid-hulled patrol boats employed during the Vietnam War from March 1966 until the end of 1971. They were deployed in a force that grew to 250 boats and were used to intercept and search river traffic in areas such as the Mekong Delta, the Rung Sat Special Zone, the Saigon River and in I Corps in the area assigned to Task Force Clearwater in an attempt to disrupt enemy weapons shipments. In that role they frequently engaged in firefights with enemy soldiers on boats and on the shoreline, were used to insert and recover Navy SEAL teams, and were employed by the United States Army’s 458th Transportation Company, known as the 458th Seatigers, the and only Army Unit to employ the Navy River Patrol Boat in Vietnam.
The Rung Sat Special Zone was the name designated during the Vietnam War by the South Vietnam Government and American forces to a large area of the Sác Forest in Viet Nam which is today known as the Cần Giờ Mangrove Forest and was also known as the “Forest of Assassins”.
The I Corps Tactical Zone was a corps of the Army of the Republic of Vietnam (ARVN) was one of four corps that made up the ARVN. The area encompassed the northernmost region of South Vietnam, bordering North Vietnam. And, it included five provinces: Quảng Trị Province, (Khe Sanh, Đông Hà, Quảng Trị City), Thừa Thiên-Huế Province, (Phu Bai, Huế City), Quảng Nam Province, (Đà Nẵng, Hội An), Quảng Tín Province, (Tam Kỳ, Chu Lai) and Quảng Ngãi Province, (Quảng Ngãi). The region included the DMZ area where 3rd Marine Division intelligence estimated the combat strength of NVA and VC forces in January 1968 was 40,943 troops.
The PBR proved a versatile watercraft having a fiberglass hull and propelled by a water jet drive that enabled it to operate in shallow and weed-choked rivers. It had a draft of just two feet of water when fully loaded, and the drives could be rotated in order to reverse the boat’s direction, turn the boat within its own length radius, and it come to a stop from full speed in the distance of just a few boat lengths.
The PBR was manufactured in two versions with the first having a 31-foot length and 10 foot, 7-inch beam. And the second, the Mark II version, at 32 feet long with a one foot wider beam and that had enhanced drives to reduce engine fouling, along with aluminum corrosion resistant gunwales.
The PBR was typically manned by a four-man crew consisting of a First-Class Petty Officer serving as the boat captain, a gunner’s mate, an engineman, and a seaman. Additionally, each crewman was cross-trained to be able to function in each other’s job in the event one became incapacitated or otherwise unable to carry out his duties. Customarily, PBRs operated in pairs under the command of a one patrol officer stationed on one of the two boats.
PBRs were powered by twin 180 Detroit Diesel 6V53N engines linked to Jacuzzi Brothers pump-jet drives that propelled them to top speeds of 28.5 knots, approx. 33 mph. Their typical armament configuration included twin M2HB .50 caliber machine guns situated forward in a rotating shielded tub, a single rear M60, one or two 7.62 mm light machine guns mounted on the port and starboard sides, and a Mk 19 grenade launcher. Additionally, their small arms complement included M16 rifles, shotguns, .45 ACP handguns, and hand grenades. And, some were equipped with a “piggyback” arrangement of a .50 cal. machine gun on top of an 81mm mortar; while others had a bow-mounted Mk16 Mod 4 Colt 20 mm automatic cannon.
However, what the boats benefited in heavy firepower they lacked in armor or shielding, and although the .50 cal. machine guns had some ceramic armor shielding and the Coxswain’s flat had some quarter inch thick steel armor plating, the boats were designed to depend on rapid acceleration,
In addition to the PBRs the Navy employed Patrol Craft Fast (PCF) In Viet Nam, also so-called Swift Boats that were all-aluminum, 50-foot long, shallow-draft vessels that initially were deployed to patrol the coastal areas and later worked in the interior waterways as part of the brown-water navy to prohibit Vietcong movement of arms and munitions, transport Vietnamese forces and to insert SEAL teams for counterinsurgency (COIN) operations during the Vietnam War.
The Swift Boat was originally conceived in a Naval Advisory Group, Military Assistance Command, Vietnam (NAVADGRP MACV) staff study designated as the “Naval Craft Requirements in a Counter Insurgency Environment,” published in 1965. It noted that COIN water operations were challenging, demanding, and unique. A prevalent belief was that COIN craft could readily be obtained from then existing commercial and naval sources when required. Unfortunately, no prior concerted effort had been made to develop COIN craft that were specifically suited to perform the variety of missions necessary to combat insurgent activities.”
The study went on to list the desired characteristics of the ideal COIN patrol craft and included that they be:
• Reliable and sturdy
• Non-wooden hull, with screw and rudder protection against groundings
• Self-sufficient for a range of a 400 to 500-mile patrol.
• Be able to acquire a top speed of 20 to 25 knots.
• Have installed a compact, high-resolution radar with a range of 4 to 6 miles.
• Have reliable long-range communications equipment, compatible with existing Army and Air Force systems
• Have the ability to operate Quietly
• Have sufficient Armament for limited offense operations
• Have limited crew berthing, but no on-board mess facility
• Have a depth meter, accurate from 0 to 50 feet.
• Have a small, powerful mounted searchlight
The study was positively received by the Navy and so they commenced a search for sources and discovered Sewart Seacraft of Berwick, Louisiana that had built water taxis for companies engaged in the oil and gas exploration industry in the Gulf of Mexico that seemed to be the ideal candidate. Subsequently, the Navy purchased their plans, and requested Sewart Seacraft to prepare modified drawings for PCFs that included a gun tub, ammo lockers, bunks, and a small galley. Then the Navy used those enhanced plans to request bids from additional boat builders, nonetheless Sewart Seacraft was selected as the finalist to provide the initial PBRs.
The “Swift Boats” were constructed having welded aluminum hulls 50 feet long with a 13-foot beam, and a draft of five feet. Their propulsion was provided by a pair of General Motors 12V71”N” Detroit marine diesel engines rated at 480 horsepower with each having with a range from 320 nautical miles at 21 knots to about 750 nautical miles at 10 knots. Their normal crew complement was six, with an officer in charge being the Skipper, Bosun’s Mate, Radioman/Radarman, Engineman, and two gunners, the Quartermaster and an additional Gunner’s Mate. Later on, in 1969 the crew was complemented with a Vietnamese trainee.
The first two boats were delivered to the Navy in late August 1965 with the original water taxi design being enhanced with two .50 caliber M2 Browning machine guns in a turret above the pilot house, an over-and-under .50-caliber machine gun – 81 mm mortar combination mounted on the rear deck, a mortar ammunition box on the stern, improved habitability equipment such as bunks, a refrigerator and freezer, and a sink. The 81 mm combination mortar mounted on the rear deck was different than the standard gravity firing mortar as used by the Army and Marine Corps, in which the falling projectile’s primer struck the fixed firing pin at the base of the mortar tube. Instead, the design was of a unique lanyard firing weapon in which the projectile was loaded into the muzzle and enabled the gunner to “fire at will” by the use of the lanyard. A similar type weapon had been tested in the 1950s but discarded when the USN lost interest in the system. However, the USCG maintained the gun/mortar system before the Navy incorporated it into the Fast Boat program. Additionally, many boats also had a mounted single M60 machine gun in the forward peak tank, just in front of the forward superstructure.
The original Navy order for 50 boats was followed up shortly with an additional order for 54 more Mark Is. Then in the latter half of 1967, an additional 46 Mark II boats with a modified deck house set further back from the bow were built. The newer boats also had round port holes replacing larger sliding windows in the aft superstructure, and then from 1969 through 1972, 33 more Mark IIIs, which were a larger version of the Mark IIs, arrived in Vietnam.
Most of the 193 PCFs that were built were used by the Navy in Vietnam and the two training bases located in California, and about 80 of the boats constructed were sold or given away to United States ally navies. The original training base for Swift Boats was the Naval Base in Coronado, California, but in 1969 training was moved to Mare Island near San Pablo Bay where it remained for the duration of the war.
The initial swift boats arrived in Vietnam in October 1965 and there were primary mission was for coastal patrol in Operation Market Time to interdict seaborne supplies being transported to the Viet Cong and the North Vietnamese Army in South Vietnam. However, their shallow draft and low freeboard limited their seaworthiness in open waters, and these limitations along with difficulties being encountered in the interior waterways by the smaller more lightly armed PBRs led to the integration of PCFs to patrol the 1,500 miles of rivers and canals of Vietnam’s interior waterways. And, although some Swift boats continued to operate in the Vietnamese littoral areas, the commencement of Admiral Elmo Zumwalt’s “SEALORDS” river way interdiction strategy, changed their primary area of operations and soon it centered in the Ca Mau peninsula and the Mekong Delta area in the southern tip of Vietnam. There, they patrolled the inland waterways and performed special operations, including gunfire support, troop insertion and recovery, and raids into enemy territory.
The Mekong Delta region was comprised of ten thousand square miles of marshland, swamps and forested sectors that all were interwoven with rivers and canals that were controlled by the Viet Cong and so the interior waterways of the Mekong Delta were instrumental for the transport of Viet Cong supplies and weaponry.
The Swift boats commonly operated in teams of three to five with each having an officer in command of it and one of them would also be placed in overall command of the mission. Their missions included patrolling the waterways, searching water traffic for weapons and munitions, transporting South Vietnamese marine units and the insertion and recovery of USN Navy SEAL teams.
When the swift boats began making incursions up the waterways and into the interior of the delta, they initially took the Cong by surprise, causing them to abandon their bounty and then escape into the underbrush. But, occasionally firefights would result as it became obvious to them that their control of the canals was being contested, so the Viet Cong developed counter-tactics to challenge the US Navy intervention. They set up ambushes and built obstructions in the canals to create choke points, and also positioned mines in the waterways.
It was always more dangerous for the swift boats when returning back down river then when going up river because their initial passage on a patrol assured their eventual return and that provided opportunities for Viet Cong ambushes. The attacks were typically brief encounters that were set up at a river bend or in a narrow canal that restricted the maneuverability of the boats And, the Viet Cong employed a wide range of portable weapons in the attacks, including recoilless rifles, B-40 rockets, .50 caliber machine guns and AK-47s, that were frequently fired from behind earthen bunkered positions. So, the engagements were brief but violent, with the enemy usually slipping away into the undergrowth after the boat crews located the source of the attacks and began to focus their return fire power at the emplacements.
Upon being attacked, the boat crews would accelerate out of the hot zone and scatter, then turn around and then return and regroup while bringing as much fire power possible to bear against the enemy. They would power past the ambush point with guns blazing, turn around again and return to attack repeatedly till the ambushers were either killed or they retreated. Though standard cruising speed at 8 to 10 knots, the boats could reach a top speed of 32 knots during attacks. The dense foliage and vegetation growth in the delta provided excellent cover for the escaping enemy and so high casualties were taken among the river crews. But, casualties suffered among the Viet Cong were difficult to assess because they would take their dead and wounded with them after a firefight, and so discovering newly dug graveyards was a rare way to confirm Viet Cong losses.
The first Swift Boat to be lost during the war was PCF-4, which was lost to a mine in 1966. Then, two other boats, PCF-14 and PCF-76, were lost in rough seas at the mouth of the Cua Viet River near the DMZ, and a fourth, PCF-77, was lost in a rescue effort during a monsoon at the mouth of the Perfume River on the approach to Huế. All of those boats were lost in 1966. And PCF-41 was lost that same year in an ambush when it was hit by fire from a 57-mm recoilless rifle; its controls were destroyed and the coxswain killed when it ran aground at speed. Then, when its crew ran out of ammunition they abandoned the vessel and although she was recovered the next day it was too badly damaged to be repaired. So, she was salvaged instead. Subsequently, PCF-43 was lost to a rocket attack in 1969 and several other Swift Boats were lost to river mines, but had been salvaged and either repaired and put back in service, or used for spare parts.
Just past midnight on 16 June 1968, PCF-19 was attacked from the air and struck by two missiles and sunk resulting in four of her crew members being killed with two were others being badly injured. The boat had been patrolling with PCF-12 near the DMZ, the 17th parallel, when it was attacked by enemy choppers.
The Swift Boat crews also had to contend with friendly fire incidents. PCF-12 commenced a running gun battle, firing its .50 caliber machine guns and zig zagging at high speed for well over an hour and its crew continuously radioed that they were under attack by an unidentified hovering aircraft, but the response from command was “no friendly aircraft in the area”. So, in order to isolate the problem, US Forces suspended all flying operations within PCF-12’s area of operation. But, despite this measure, PCF-12 continued to be engaged with the enemy.
It had been theorized by both officers and men of the U.S. Army, USMC, and USN that the “NVA” were operating helos at Tiger Island, located just off the North Vietnamese coast. And, hovering aircraft had been seen near the DMZ by U.S. Marines on shore too. Official reports, such as OIC and the PCF-12s Combat After Action Report for “Market Time Patrol,” mentioned in part “...enemy held Tiger Island...possible base of operations for North Vietnamese military...” and “under constant air attack from all angles, Helo gunners ordered to fire the .50 caliber guns at any and all air contacts....” Declassified official reports note “enemy aircraft” did in fact operate in the area. Enough evidence was presented to conclude that the loss of PCF-19 was due to fire from a helicopter aircraft operated by or for the North Vietnamese.
As of 2006, the attack upon PCF-12 and PCF-19 is still regarded by the US Navy as a friendly fire incident.
A personal account of the action seen by PBR crew’s goes like this;
I served in Nam from April 69 to April 70 and I was in assigned to a PBR and initially served on the boat for two months as a third-class gunner’s mate. Later on, I was made boat captain and given a field promotion to 2nd class Petty Officer. Then, when my boat was damaged in a fire fight in operation Giant Slingshot I was reassigned to another where we had set an ambush along with Long Range Patrol Army personnel. And, they went out about 300 yards to set up the ambush, but NVA got between us and waited for the heavies to come by. They shot through us not knowing we were there and we did not know they were there. The troop transports did not know we were there. The NVA attacked the transports and the transports fired back through us and we fired at the NVA killing one officer and the army fired at the NVA. It was a four-way fire fight with us and the NVA stuck in the middle. I was wounded in the arm and the boat received 100 or so bullet holes. But, still we were able to make it back to the floating base.
After that, we took the boat back to NhaBe and I was assigned a new command again where I stayed until we lost an engine. So, I was reassigned again to a very decent boat and it was by far the fastest of any of our division boats. The boat repair at NhaBe had installed fiber-glassed chines on the hull and this caused the boat to get on plane faster and skim the water surface better. We were assigned a new patrol area above Saigon which s was even a hotter area and we were shot up bad in a fire fight. But since I needed to get one more patrol completed before our crews could get some R&R and some rest at NhaBe.
So, I asked if I could borrow another PBR one night to get our patrols in and I promised that I would set up a safe ambush so as not to damage the borrowed boat. Everything went well and afterwards we were heading back to base when I looked up to see a B40 rocket coming in at us and the boat took the hit below the water line and that took out the starboard engine. Quickly, the boat was riddled with small arms hits but no one was injured. So, I jumped into the water and plugged the hole with a life jacket. Since we were close to the base, the rest of the boats scrambled to help us out. But, my PBR didn’t have a port engine so we tied two boats together and used their outboard engines to get us back to NhaBe where we stayed at for 3 days, and then I was reassigned to another PBR that I kept until I left Nam. In all I ran 289 patrols and was involved in 18 fire fights.
The Swift Boats and PBRs were retired from active duty by the U.S. Navy immediately following the Vietnam War during the early 1970s. However, they continued operating with the U.S. Naval Reserve units up until 1995 at Mare Island, California prior to the base’s closure due to Defense Base Closure and Realignment Commission (BRAC) action that year. During the Vietnam War, Mare Island was home to the U.S. Navy’s Repair Facilities, Mothballing Operations, Submarine Operations, and Riverine Training Operations for both Swift Boats and PBRs.
The Vietnam People’s Navy managed to receive a number of South Vietnam’s defunct Navy PCFs after the unification of Vietnam in 1975 and they were quickly put into service in the PAVN’s operation at Thổ Chu and other islands to repel the invasion of the Khmer Rouge. The swift boats are still active in the current Vietnam Navy.