The Brown Water Navy in Vietnam

by

Robert H. Stoner, GMCM (SW)(Ret)

[Part 1 covered Operation MARKET TIME. In Part 2 we will look at Operation GAME WARDEN. This is operation took the war from the coastal regions, up the river deltas, up the rivers and into the canals of South Vietnam.]

The naval war in South Vietnam during the years 1964 to 1975 was very dynamic. For the Americans aiding the South Vietnamese, the effort was several fold: (1) build and equip a capable Vietnamese Navy; (2) teach the new VNN how to fight; (3) how to keep itself supplied; and (4) how to keep itself operational.

At the same time, the United States Navy found itself embroiled in a war that was fought at first, off the coastal waters of South Vietnam, and then in the river deltas, smaller waterways and canals of the country. To combat North Vietnamese infiltration of men and supplies by sea, three Task Forces were formed: TF-115 called Operation MARKET TIME; TF-116 called Operation GAME WARDEN; and TF-117 called the MOBILE RIVERINE FORCE (a joint amphibious Army-Navy riverine operation).

Operation GAME WARDEN

Task Force 116 was established on December 18, 1965 and given the name Operation GAME WARDEN. During the Vietnam War, there were over 50 LSTs serving in direct support of the Navy’s Brown Water forces. The LSTs in Vietnam earned 360 battle stars, 19 Presidential Unit Citations (PUC), 45 Navy Unit Citations (NUC), and 39 Meritorious Unit Citations (MUC).

By mid-1968 and just prior to the Tet Offensive, the compliment of PBRs was increased to 250. Patrol areas were expanded into I Corps and even into Cambodia under Operation SEALORDS (South East Asia Land, Ocean, River, and Delta Strategy) in the fall of 1968.

The original Game Warden TF-116 consisted of the following units:

Support Ships (1966)

· USS BELLE GROVE (LSD-2)
· USS COMSTOCK (LSD-19)
· USS TORTUGA (LSD-26)
· USS FLOYD COUNTY (LST-762)

Support Ships 1967-1968

◊ 4 specially modified Landing Ship Tank (LST)
· USS GARRETT COUNTY (LST-786)
· USS HARNETT COUNTY (LST-821)
· USS HUNTERDON COUNTY (LST-821)
· USS JENNINGS COUNTY (LST-846)
· 20 Landing Craft (LCVP)
· 8 UH-1B Huey Helicopters
· 120 specially designed River Patrol Boats (PBRs)

◊ River Patrol Force (PBR)
· River Division 51 Can Tho / Binh Thuy
· River Division 52 Sa Dec (later Vinh Long)
· River Division 53 My Tho
· River Division 54 Nha Be
· River Division 55 DaNang

Four LSTs were specially configured as mobile PBR bases. The original Operation Game Warden LSTs were: USS GARRETT COUNTY (LST-786), USS HARNETT COUNTY (LST-821), USS HUNTERDON COUNTY (LST-838) and USS JENNINGS COUNTY (LST-846). Specialized LST modifications included:

· A day and night landing area for UH-1 helicopters.
· Refuel and rearm facilities for the gunships were provided.
· Four boat booms for mooring up to 16 PBRs alongside the ship.
· A cargo boom to lift PBRs out of the water repairs aboard ship.
· Repair shops to do engine, pump, hull, and repairs on PBRs.
· Fresh water distillation was improved for the increased manning.
· Upgraded radio, navigation, and electronic equipment installed.

The LSTs provided important supply and maintenance facilities for the PBRs (and other small boats). Many of these services were unavailable at shore bases. After the modifications, the LSTs had so much new equipment stuffed into their hulls that living conditions for crews were seriously overcrowded.

Below: The LSTs that supported Operation GAME WARDEN saw lots of service – some spanning three wars – World War 2, Korea, and Vietnam. USS JENNINGS COUNTY (LST-846) was typical of those unsung warriors that accomplished great things. Like the sailors that man them, ships earn and wear awards and decorations. Jennings Country earned a lot of them over her long service. Here is her awards and decorations in order of precedence (top to bottom, left to right): Combat Action Ribbon, Presidential Unit Citation, Navy Unit Citation, China Service Medal, American Campaign Medal, Asiatic-Pacific Campaign Medal, WW2 Victory Medal, Navy Occupation Medal (Asia Service), National Defense Service Medal, Korean Service Medal (2 awards), Vietnam Service Medal (9 awards), Vietnamese Cross of Gallantry Citation (w/palm), Vietnamese Civil Actions Citation (w/palm), United Nations Service Medal, Vietnamese Campaign Medal, Korean War Service Medal.

Areas of operation for the four GAME WARDEN floating bases were the Bassac, Co Chien, and Ham Luong Rivers. A rotation plan was set up where three GAME WARDEN units were always on station while the fourth was out of Vietnam for R&R (rest and recuperation) and repairs. In most cases, repairs were in the Philippines and lasted for one to two months at a time.

The flat-bottomed LSTs could navigate upstream all the way to the Cambodian border using the rivers of the Mekong Delta from multiple entrances from the South China Sea. Although the LSTs made it possible to project a mobile support base for PBR boats and helicopters deep inland, putting such large slow moving ships like these on narrow waterways surrounded by dense jungle presented risks.

On September 12, 1968, USS HUNTERDON COUNTY was ambushed near Ben Tre. She was hit by rocket and recoilless rifle fire from shore and suffered extensive structural damage. Two crewmen were killed and another twenty-five were wounded.

The PBRs (Patrol Boat, River) became known as the mainstay of river patrol operations. But, when the Navy decided to commit itself to river patrol operations in Vietnam, it did not have a readily available small fast patrol craft, nor did it have time to design one of its own. The Navy decided to find a commercially available hull and modify it for combat. They needed a small, light boat with high speed, shallow draft, water jet propulsion system, and heavy firepower. A contract for 120 PBRs (called Mark I) was awarded to United Boat Builders (Uniflite) of Bellingham, Washington at a cost of $75,000 each.

The Mk I PBR had a 31-foot long fiberglass hull. It could do 28 knots and was powered by two GM 6V53 220 hp diesel truck engines that gave 2,800 rpm direct drive to the Jacuzzi water jet propulsion pumps. Each boat carried a Raytheon 1900 radar unit for night operations. Armament consisted of twin .50 machine guns in a gun tub on the bow, a single .50 machine gun was aft, two M60 7.62 NATO caliber machine guns (or one M60 and one Mk 18 40mm grenade launcher) were on armored shields amidships, plus the personal weapons of the crew. Later, some PBR crews “augmented” firepower with such weapons as 57mm and 90mm recoilless rifles, M72 light anti-tank weapon (LAW) rocket launchers, flamethrowers, 7.62 NATO Mini-guns, 60mm mortars, or 20mm cannon.

The crew of a PBR was four men -- A first class or chief petty officer, a gunner's mate, an engineman, and a seaman. Each man was cross-trained to do the other man’s job if he was wounded or killed. PBRs operated in pairs and patrolled the various rivers and canals day and night. The PBRs searched sampans and junks for weapons and supplies. The Viet Cong were very good at concealing such material in even the smallest of boats. Only by thoroughly checking every boat could the flow of weapons and supplies be stopped.

The PBR crews (along with the rest of the GAME WARDEN fleet carried out this mission so effectively that movement of supplies to the Viet Cong by these waterways was severely curtailed.

Other GAME WARDEN Units

Task Force 116 was more than just LSTs and PBRs. Task Force 116 also included Naval Special Operations Groups including: Mobile Support Team ONE, Mobile Support Team TWO, Beach Jumper Unit ONE, Assault Craft Unit ONE, Harbor Clearance Unit ONE, SEAL Team ONE and TWO, Underwater Demolition Team 12 and 13, Explosive Ordnance Disposal detachments. Also included were Strike Assault Boat Squadron 20 (StabRon 20); a Patrol Aircushion Vehicle Squadron (PACV); and Naval Support Activities (to man the forward bases ashore and afloat).

Taken together, these units fielded some very interesting and diverse craft. Ships and boats and other vehicles engaged in Operation GAME WARDEN were: Landing Ship Tank (LST), Landing Craft Vehicle-Personnel (LCVP – 1966-1971), Patrol Boat River (PBR), STrike Assault Boat (STAB – 1970), SEAL Team (aka Tactical) Assault Boat (STAB – 1967 to 1968), Heavy SEAL Support Craft (HSSC – 1966-1971), Medium SEAL Support Craft (MSSC – 1969-1971), Light SEAL Support Craft – 1968-1971), Landing Craft Personnel, Large Mk 4 (1967-1969), Boston Whaler (13-foot – 1966-1971), Kenner Ski Barge (17-foot – 1968-1971), Inflatable Boat Small (IBS – 1966-1971), Landing Craft Mechanized Mk 3, Mk 6, and Mk 8 (1966-1971), Patrol Air Cushion Vehicle (PACV – 1966-1968), Landing Craft Utility (LCU – 1966-1971), and Swamp or Air Boats (1967-1971).

LST – LST-542-class tank landing craft

Above: The 328-foot USS GARRETT COUNTY (LST-786) was a LST-542 class World War 2 built ship. In this photo the ship is shown with her brood of PBRs, boat booms, and the boat lift crane. [Photo: Gerald Busic]

Below: USS HARNETT COUNTY (LST-821) was also home to the Navy Seawolf UH-1B gunships of Light Helicopter Attack Squadron 3 (HAL-3). Two alert birds are spotted on her foredeck ready to launch. [Photo: Seawolf.org]

Above: An Army CH-47A “Chinook” heavy-lift helicopter in the process of hooking up a damaged UH-1B Seawolf helicopter for transportation to NAS Binh Thuy for repairs. The photo was taken aboard USS HARNETT COUNTY (LST-821). [Photo: Seawolf.org]

Below: USS HARNETT COUNTY (LST-821) shows off her boats and helicopter facilities in this photo. The helicopter in the center is an UH-34 Sea Horse admin helicopter, a UH-1B gunship is to the right. Judging by the mud and sand stirred up, the waters must be quite shallow in this anchorage. [Photo: Ed Pietzuch]

LCVP – Landing Craft Vehicle-Personnel (LST ship’s boat)

Below: The LCVP was a World War 2 design by Higgins Industries in New Orleans, LA. It was a 36-foot boat designed to move troops, cargo, or small vehicles like Jeeps from ship to shore. An LCVP was crewed by three men: coxswain, boat engineer and a seaman. When the machine gun mounts were fitted, the latter two manned the guns. Later LCVP models were made of fiberglass instead of wood. A ¼-inch steel armored plate was fitted on both sides of the hull to offer some protection to the occupants. The boat had a diesel engine and a single prop. The prop, shaft, and rudder were protected by a skeg when the boat was driven onto the beach. LSTs carried two or four LCVPs on davits. [Drawing: US Navy]

Above: An LCVP from USS DRAKE (APA-159), heavily loaded with troops, heads to the beach in World War 2. [Photo: US Navy]

PBR – Patrol Boat River, Mark I

Above: One of the 120 Mk I PBRs deployed to Vietnam in 1966. The PBR was a commercial design adapted for patrol work. Left, Mk I PBR number 138 heads out on patrol. Right, two Mk I PBRs demonstrate how the boats patrolled in pairs: one boat would assume the lead and the other boat would cover it. If either boat were attacked, the other boat would engage the attackers to catch them in crossfire. One hundred sixty-one PBRs were delivered in 1966. [Photos: Lee Wahler]

Below: A good profile shot of the Mk I PBR. [Photo: Lee Wahler]

Above: This Mk I PBR is being brought aboard USS GARRETT COUNTY (LST-786) for maintenance. The running lights, radome, and pilothouse cover have been removed or relocated for the lift. [Photo: Gerald Busic]

PBR – Patrol Boat River, Mark II/III

Above: The Mk II PBR was brought into service in 1967. The Mk II was a redesign of the Mk I to incorporate lessons learned in Vietnam. The Mk II introduced a redesigned forward twin gun mount, in increased size pilothouse with additional armor for the coxswain, and the hull was strengthened – especially where the main deck and hull join. Left, a Mk II plows at low speed on patrol. Right, like other PBRs, the Mk II was very maneuverable and could turn within its own length. In this photo, a Mk II does a crash turn to starboard. [Photos: Lee Wahler]

Above: A Mk III PBR. Eighty-seven Mk II PBRs were brought into service in 1967-1968. The Mk III was externally indistinguishable from the Mk II. The Mk III was the most numerous variation of the PBR: 145 were delivered in 1968-1969; 37 were delivered in 1969-1970; 23 in 1970-1971, 30 in 1971-1972; 10 in 1972-1973; 37 in 1973-1974; and 7 in 1976-1978 (289 total). The last 5 operational Mk III PBRs belong to Special Boat Team 22 in Stennis, MS. One of the SBT-22 boats is shown here completing a sharp starboard turn. [Photo: US Navy]

STAB – STrike Assault Boat

Above: The STAB was the brainchild of ComNavForV, VADM Elmo R. Zumwalt. The boat was designed around the 24-foot Light SEAL Support Craft (LSSC) built by Grafton Boatworks, Grafton, IL. The STAB boat was lengthened from 24 feet to 26 feet and the propulsion changed from two 427 Ford gasoline engines and Jacuzzi water jet pumps to two 427 Chevy gasoline engines and MerCruiser stern drives. [Photo: Tom Lefavour]

Above: The STAB was the fastest boat deployed to Vietnam – 20 were deployed there during the year 1970 with StabRon 20. [Photo: Dan Kurant]

Below: Three boats of StabRon 20 returning from an operation. Note the heavy armament used on the STABs – M60 machine guns and 40mm grenade launchers. The LSSC used by MST-2 units were more lightly armed because they could rely on the SEAL squad’s firepower if they were ambushed. The STABs relied on more firepower with less manpower. [Photo: Dan Kurant]

Naval Special Operations Craft (MST-1, MST-2)

Mobile Support Team ONE predated Operation GAME WARDEN. MST-1 was established in early 1964 to conduct covert missions against North Vietnam by VNN-crewed boats whose crews were trained and the boats maintained by USN personnel. These boats were drawn from Boat Support Unit ONE, Coronado, CA and were called PTF (Patrol Torpedo, Fast). The PTF was actually a misnomer, because this multi-purpose boat was designed function as either: (1) a patrol torpedo – PT – boat; (2) a motor gunboat; or (3) a fast minelayer. The USN used the PTF as a motor gunboat throughout its service (1962 to 1979). MST-1 operated from Da Nang, Vietnam.

Operational control of the PTFs in Vietnam was through the Military Assistance Command, Vietnam - Studies and Observation Group (MACV - SOG). SOG was a joint unconventional warfare command that integrated many different units of the American armed forces and intelligence community. MACV-SOG was established on 24 January 1964.

Under SOG auspices, the American sailors of MST-1 trained the VNN in PTF operation and maintained the PTFs under their care. The VNN crews took the PTFs into North Vietnamese waters to raise all kinds of particular hell. Over 1,000 of these OP 34A raids were conducted by the VNN from March-April 1964 until January 1972. In January 1972, all PTFs were transferred back to the custody of the USN and brought back to the United States.

There were a total of 26 PTF boats that could be divided into four general groups: (1) the Legacy Group – PTF 1 (ex-PT 810) and PTF 2 (ex-PT 811); (2) the Nasty Group – Norwegian boats PTF 3 through PTF 16; the Trumpy Group – U.S. built boats PTF 17 through PTF 22; and the Osprey Group – U.S. built boats PTF 23 through PTF 24.

Of the four groups, the PTF 1 and PTF 2 were Korean War-era prototype PT boats that had been refurbished for Vietnam service. The boats were aluminum construction, the engines burned 115/145 octane aviation gasoline, and parts were difficult to find for them. These boats were discarded as soon as possible and replaced by the modern Norwegian Nasty-class boats.

There were 14 Nasty-class boats purchased from Norway by the USN; PTF 3 through PTF 8 were taken directly from Norwegian Navy stocks and PTF 9 though PTF 16 purchased from the Norwegian builders. These boats were delivered from 1962 through 1966. All Nasty-class boats were 80 feet by 24 feet, of wooden construction and weighted 75 tons.

There were 6 Trumpy-class boats purchased from Trumpy and Sons, Annapolis, Maryland for the USN and delivered in 1968 and 1969. The Trumpy boats were very similar to the Nasty-class boats, but were differences in internal arrangement, in engineering, and in the electronics carried. Construction, dimensions, and weights were the same as the Nasty-class boats.

There were 4 Osprey-class boats purchased from Stewart Seacraft in Berwick, Louisiana for the USN and delivered in 1968. The Osprey-class was aluminum construction, 95 feet by 24 feet, and about 125 tons.

PTF – PTF 1, PTF 2, Nasty-class, Trumpy-class, Osprey-class (patrol torpedo, fast)

Below: The 89-foot PTF 1 (ex-PT 810) built by Bath Iron Works for the USN in 1951. The boat was aluminum, weighed 95 tons, and had four Packard marine engines burning 115/145 octane aviation gasoline. This boat became PTF 1 in 1962 and was one of the first four craft sent to MST-1 at Da Nang, RVN in early 1964. All USN PTFs were on-loan to the VNN and no PTFs were transferred to the VNN. [Photo: Jim Gray]

Below: The 95-foot PTF 2 (ex-PT 811), built by John Trumpy and Sons for the USN in 1951. The boat was aluminum, weighed 95 tons and had four Packard marine engines burning 115/145 octane aviation gasoline. This boat became PTF 2 in 1962 and was one of the first four craft sent to MST-1 at Da Nang, RVN in early 1964. [Photo: US Naval Institute]

Above: PTF 3 was a Nasty-class motor gunboat. She is shown at top speed in Manila Bay during February 1964. This boat was one of four that began operations from Da Nang, Vietnam in March-April 1964. All PTFs were shipped through the Philippines prior to deployment to Vietnam. The MST-1 repair shops at Subic Bay, made changes to the boats to prepare them for war. One of the changes was to remove the forward 40mm Bofors gun and replace it with the Navy Mk 2 Mod 0 81mm mortar. The mortar was used for indirect fire and for illumination of North Vietnamese targets. [Photo: Mark Tondel]

Below: PTF 7 is seen next to USS SAINT PAUL (CA-73) at Subic Bay Naval Base. The sleek lines of the PTF are well shown in this photo. The Mk 2 Mod 0 81mm mortar is installed forward of the bridge under the gray cover. [Photo: Robert T. Webb]

Above: PTF 21 is seen at top speed off Hawaii about 1972. One of six Trumpy-class boats, she differed in minor details from the Nasty-class.

Note the difference between the Decca and Litton radar antennas and ammunition box arrangement. [Photo: Chip Marshall]

Below: PTF 23 was the lead boat of the Osprey-class. Of aluminum construction, the Ospreys were 15 feet longer than the Nasty and Trumpy boats. As can be seen from the photos, the superstructure of the Osprey was quite different from the earlier PTFs. The Ospreys were designed to take gas turbine engines, but they were never installed. The Ospreys used the same Napier Deltic T18-37K turbo-supercharged diesels of the Nasty and Trumpy boats. [Photos: Warboats.org]

Mobile Support Team TWO was established in 1967 to provide boat support for Navy SEAL Teams and UDT Detachments assigned to the Republic of Vietnam. Early SEAL operations (begun in 1966) had relied on SEALs operating their own makeshift craft. It soon became obvious that the SEALs and UDTs were needed fulltime for their tasks and the boat support needed to be spun-off to a dedicated unit. Boat Support Unit ONE created Mobile Support Team TWO that had its headquarters at Binh Thuy. Binh Thuy was on the Bassac River, a couple of miles from the large city of Can Tho. The MST-2 OIC (officer-in-charge) shared his office with the SEAL/UDT OIC. Together, they were responsible for all the boat and special operations in Vietnam from Saigon south to the tip of the Ca Mau Peninsula.

Special operations craft in Vietnam went through continuous development and improvement through the years 1966 through 1971. Roughly speaking, we can trace this as:

1966 – ST-1 personnel are using at least one LCPL fitted with armament and a modified LCM-6 (Heavy SEAL Support Craft 1) as well as Boston Whalers and the ubiquitous IBS (inflatable boat, small).

1967 -- ST-1 modified HSSC 1 is heavy damaged (on two occasions) by direct mortar hits; MST-2 brings two purpose-built HSSCs (HSSC 2 and HSSC 3) to Vietnam along with four modified LCPLs. ST-2 brings two STAB (SEAL Tactical Assault Boats) to Vietnam. MST-2 also uses Boston Whalers and the IBS on some operations.

1968 -- STAB boats and Boston Whalers are retired from tactical operations in favor of the new Light SEAL Support Craft (LSSC); HSSCs and LCPLs continue in use. Some use of Kenner Ski Barges and Boston Whalers are used for non-tactical operations.

1969 -- LCPLs are phased-out in favor of the Medium SEAL Support Craft (MSSC). HSSCs and LSSCs continue in use.

1970-1971 -- All SEAL/UDT support is done with LSSCs, MSSCs, and HSSCs. There is some use of Boston Whalers and Kenner Ski Barges, but not for tactical ops. One HSSC is lost in a storm in the Gulf of Thailand, January 1971. All MST-2, SEAL, and UDT units stand down in November 1971.

1966 – LCPL, HSSC, Boston Whalers, IBS

Above and below: SEAL Team ONE at Nha Be was forced by circumstances to scrounge boats and modify them for use in Vietnam. Here ST-1 members are in the process of converting an LCM-6 that became known as the “Mighty Mo” due to its armor and heavy armament of 7.62 NATO, .50 machine guns, a 60mm mortar, a 57mm recoilless rifle and a Mk 18 40mm grenade launcher. [Photo: Frank Anderson]

Above: A Mk 4 LCPL as hastily modified by members of ST-1. Some guns lack armored shields to protect the gunners and the crew is much too exposed. Whether it was used on operations is not known. [Photo: Chuck LeMoyne]

Below: The ubiquitous IBS was an inflatable boat that traced back to the days of the Navy Combat Demolition Units and Underwater Demolition Teams of WW2 and Korea. This IBS belonged to MST-2 detachment Alpha at My Tho. [Photo: Jim Born]

1967 – LCPL, HSSC, STAB, and Boston Whaler

Above: A rare shot of a Mk 4 LCPL conversion by BSU-1 as part of Project ZULU. The LCPL has been fitted with heavy machine guns, gun shields and additional armor. Four LCPLs would be converted and were heavily utilized by MST-2 from 1967 through 1969 when they were replaced by the new MSSC. The problem that plagued both the Project ZULU conversions of the LCM-6 and LCPL Mk 4s were their lack of speed. This was not solved until the advent of the LSSC and MSSC. [Photo: Tom Hawkins]

Below: Loaded with SEALs and MST-2 personnel, this LCPL is on its way to an insertion somewhere near Can Tho, Vietnam. [Photo: Tom Hawkins]

Above: The MST-2 LCPL noses into the beach to insert its SEALs. Whether this is a practice insertion or actual mission is unknown. Most missions like this were conducted at night. (Photo: Tom Hawkins]

Below: A bow-on shot of the LCPL nosing into the beach for an insertion. The presence of the photographer on the shore and the background suggest this is a practice insertion for the camera. [Photo: Tom Hawkins]

Above and below: The LCM-6 conversion by ST-1 was called the “Mighty Mo” due to its heavy armament. This was the first of the Heavy SEAL Support Craft (HSSC). Two MST-2 purpose-built HSSCs replaced the ”Mighty Mo” in mid 1967. [Photos: Jerry Clark (upper); Erasmo Riojas (lower)]

Above: Three photos of the SEAL Tactical Assault Boat at Little Creek, VA. Two of these boats were brought to Vietnam by ST-2 in 1967. [Photos: Tom Hawkins]

Above and below: The third STAB of ST-2 under going air transport trials by a CH-46 “Sea Knight” helicopter at Little Creek, VA. On one trial, the straps holding the boat failed and it was sent crashing into a parking lot on base where it demolished a car. This boat was used for weapons immunity trials before being scrapped. [Photos: Tom Hawkins]

Above: Members of ST-2 and MST at Nha Be attend a pre-operation briefing before setting out in their STABs. [Photo: LIFE Magazine via Jim Gray]

Below: A shot of STAB 1 underway. Note how low the transom sits relative to the water. This feature caused the capsizing of the STABs on several occasions and several SEALs and LDNNs (Vietnamese SEALs) were hurt. [Photo: Jim Gray]

Above: The two STABs of MST on their way back from an operation. This was not a time to relax as shown by the SEAL scanning the riverbank and ready to return any enemy fire. [Photo: LIFE Magazine via Jim Gray]

Below: Mission completed, one of the STABs is pulling up to the pier at Nha Be. The fellow at the far left is a Vietnamese LDNN while some of the SEAL operators are still wearing their inflatable life jackets. [Photo: LIFE Magazine via Jim Gray]

Above: A well-worn STAB comes up to the LCPL with detainees aboard. The detainees would be questioned and their identity papers checked. If they were OK, they’d be released. If not, they’d be taken back for more questioning. [Photo: Gary Smity]

Below: The same LCPL with its two detainees aboard. There were no good roads in the Delta and so everyone, friend and foe, took sampans. These detainees may be innocent villagers or fishermen or VC. Time will tell. [Photo: Gary Smity]

Above: A factory-fresh 13-foot Boston Whaler at the BSU-1 piers at Coronado, CA. The Whaler was a very robust boat, but got very cramped when you put MST and SEALs aboard it. [Photo: Tom Hawkins]

Below: An MST-2 crew checking the papers of a Vietnamese sampan’s occupants. These people could be innocent civilians or VC trying to smuggle arms and supplies. [Photo: Bill Moreo]

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Above: MST modified their Whalers to move the coxswain to the center of the boat and added armor plate to protect him. A similar plate was added to the bow to afford some protection for the gunner. MST crews put the same engines as the STABs on their boats to give them greater speed. [Photo: Bill Moreo]

Below: It did not take long to use up what space there was in the Whaler. Here two Nha Be Whalers move out on an operation with some “visitors.” Both boats have been modified to place the coxswain in the center of the craft behind some armor plate and put the radio next to him. [Photo: Randy Miller]

Above: An overhead view of the MST-modified Whaler showing the added armor plate for both the coxswain and gunner. Note the radio location to the coxswain’s left. [Photo: Randy Miller]

Below: Sometimes operations with the Whalers required a tow from the LCPL. In this photo, both Nha Be MST-run Whalers are towed by the LCPL. If SEALs were along for the operation, they would be aboard the LCPL due to safety and room considerations. There wasn’t a lot of protection on a Whaler if you were ambushed and the best tactic was to run away as fast as you could go. [Photo: Bill Moreo]

1968 – HSSC evolution, Kenner Ski Barge, and LSSC

Above: HSSC evolution (Can Tho boat). As received as part of Project ZULU in 1967, this HSSC had no armor for the engine room and a soft top. The Can Tho boat can be recognized by the diamond-shaped ballistic plates to protect the well deck gunners from incoming shots. Two MST-2 LCPLs are outboard of the HSSC. [Photo: Jim Gray]

Below: The same boat after the fitting of armor around the engine room. A solid deck replaced the well deck soft top. This deck was capable of supporting a UH-1 helicopter. [Photo: Jim Gray]

Above: The Can Tho HSSC with its first major armament upgrade – an M40A1 106mm recoilless rifle. [Photo: Tom Hawkins]

Below: Loading a 106mm round into the recoilless rifle. The .50 spotting gun was used to put the 106mm round on target. The gunner, wearing sound powered phones, sits on the tripod leg. [Photo: Bill Moreo]

Below: The next major armament upgrade to the Can Tho boat – a GAU-2B/A (M134) 7.62 NATO Mini-gun (rotary barrel machine gun). Note the gun smoke from the Mini-gun that partially obscures the recoilless rifle barrel. [Photo: Bill Moreo]

Above: The Can Tho HSSC prior to its last major upgrade in 1969. This last upgrade replaced the Mk 2 Mod 0 81mm mortar (gray object in side lowered bow ramp) with the Mod 1. The Mk 2 Mod 1 was an over and under rig with a .50 machine gun above the 81mm barrel. At the same time, bar armor was installed from the armor bulge around the engine room to the bow ramp. Bar armor had proved very effective on similar LCM conversions used by the Mobile Riverine Force (TF-117). [Photo: Don Crawford]

Below: Typical bar armor arrangement on command and control boat CCB-18 (now a memorial at Coronado, CA) as seen from the stern starboard side. The space between the hull and bar armor was filled with Styrofoam blocks to absorb shrapnel from projectile explosions. The bar armor was very effective against rockets, but less so against recoilless rifle fire. [Photo: Lee Wahler]

Above: The evolution of the Nha Be HSSC was similar to the Can Tho boat. However, the Nha Be boat was different in appearance. Note the square armor around the pilot house, different armor plating around the engine room spaces and overhead cover for the well deck. The boat is seen here at low tide in mid 1967 and before armament upgrades were made. [Photo: Randy Miller]

Below: The first armament upgrade to the Nha Be HSSC was the addition of an M40A1 106mm recoilless rifle and sand bags over the solid helicopter landing pad. Left, the HSSC beached in the RSSZ. Right, a close-up of the recoilless rifle and the sand bag “armor” on the well deck overhead cover.

Below: Close-up of the conning station on the Nha Be HSSC. Note the long box at the back of the sunroof. This box carried all the boat’s radio equipment. Various antennas, including the radome for the radar and running lights, attached to the sunroof. Armor for the conning station was arranged in the form of a box on the Nha Be boat; the Can Tho boat’s armor was roughly octagonal in shape. [Photo: Randy Miller]

Above: The next armament upgrade to the Nha Be HSSC was the addition of a large gun tub for twin .50 machine guns. Unlike the Mini-gun tub for the Can Tho boat, the tub on the Nha Be boat was not attached to the edge of the helicopter deck. The helicopter deck has been reinforced to land a UH-1 helicopter and the sand bags have been removed. [Photo: Ron Allen]

Above: A portside view of the Nha Be HSSC. Note the gap between the edge of the top deck with the M40A1 recoilless rifle and the twin .50 gun tub. [Photo: Ron Allen]

Below: Another look at the arrangement of the Nha Be HSSC. It is not known whether this boat received the bar armor upgrade of the Can Tho boat. [Photo: Ron Allen]

Above: Detail shots of the twin .50 gun tub, shields, and ammunition supply for the guns. Left, the .50 machine guns were set side-by-side and had extended oversize ammunition boxes. The extent of the boxes can be seen behind both crewmen. Right, the twin guns and their oversize ammunition boxes from the gunner’s position. [Photos: Ron Allen]

Below: In addition to the Boston Whaler, the Kenner Ski Barge was larger and wider. Often called a “Boston Whaler”, the Kenner was 17 feet long and mounted two outboard engines. The Kenner had a pedestal mount for an M60 machine gun, a distinctive side railing on both sides, and the coxswain sat at his station in the rear by the twin outboards. Shown here is one of the Kenner boats belonging to MST-2. [Photo: Dave Porter]

Below: An MST-2 LCPL alongside an Ammi pontoon. Each of the four Mk 4 LCPLs used by MST were slightly different. This LCPL has a single .50 machine gun forward. The sunroof of this LCPL is being repainted – the yellow color is the primer coat that was applied just before the final green paint coat and aircraft recognition marking. An LSSC is nested outboard of the LCPL. [Photo: Rick Erwin]

Above: The MST-2 detachment at Vinh Long had an LCPL that had twin .50 machine guns behind a custom armored gun shield. The center plate was designed to stop straight-on shots from hitting the gunner. [Photo: Bill Strawbridge]

Below: The MST-2 detachment at Nam Can used a 7.62 NATO Mini-gun in the bow position and had a Navy Mk 4 60mm mortar next to it. [Photo: John Engstrom]

Above: A brand new LSSC on the Mississippi River near Grafton Boatworks, Grafton, IL in 1968. Grafton delivered 16 LSSCs to the USN during 1968 and early 1969. The LSSC replaced the worn-out STABs and Boston Whalers (and Kenner Ski Barges) for SEAL and UDT operations. [Photo: Tom Hawkins]

Below: When a load of SEALs went aboard the LSSC, it got rather crowded as shown here. This LSSC is on a training exercise in 1968. [Photo: Tom Hawkins]

Above: A new LSSC drops off its SEAL squad during training operations in 1968. The LSSC saw much hard fighting during 1968 to 1971. [Photo: Tom Hawkins]

Below: Its SEALs inserted, the same LSSC retracts from the shore. The LSSC would then move to a pre-arranged pickup point and act as a radio relay link while the SEALs were in the field. [Photo: Tom Hawkins]

Above: The LSSC typically carried a .50 machine gun and two or more M60 or M60D (shown here) machine guns. The excellent condition of this boat indicates this picture was taken in early to mid 1969. By 1970, operations dictated the removal of the Raytheon 1900 radar and its cumbersome radome. The radar was not very useful on the small rivers and canals where the LSSC operated and the radome was seen as a B-40 rocket shrapnel hazard. [Photo: Jim Gray]

Below: An LSSC operating with the LCPL just ahead. A Vietnamese LDNN (SEAL) is standing on the bow, while a SEAL with an M60 machine gun is standing just behind him and to the left. SEALs would do insertions and extractions over the bow of the LSSC. Many MST detachments removed the forward firing M60s as an aid to the SEALs’ movement on and off the boat. The forward guns were relocated amidships with the .50 covering the after part of the boat. [Photo: Jim Gray]

Above: The Navy was fascinated by the idea of flying the LSSC from one location to an other behind enemy lines. This was the origin of the STAB (STrike Assault Boat) concept that created StabRon 20 (1970). However, the LSSC fared no better at airlift than the STAB of ST-2 had at Little Creek, VA in 1967. On the third LSSC lift, the slings supporting the boat failed and the boat fell into a rice paddy from about 3,000 feet. The boat engines kept right on going at impact with the ground. Tactical aircraft bombed the remains. [Photo: Jim Gray]

1969-1971 – MSSC and LSSC Evolution

Above: The replacement for the venerable LCPL was the Medium SEAL Support Craft (MSSC). This 36-foot aluminum boat was built by Atlantic Research Corporation in Costa Mesa, CA. Ten of these boats were delivered in 1969 for use by MST detachments in Vietnam. The MSSC carried 300 gallons of gasoline in four bladders low in the hull. Propulsion was by two 427 Chevy gasoline engines and two MerCruiser stern drives. The MSSC became the workhorse for SEAL/UDT boat support units until November 1971 when all NSWG units were withdrawn from Vietnam. Here, an MSSC is fitting out at the builder’s pier in Costa Mesa. [Photo: Tom Hawkins]

Below: The 36-foot MSSC was designed for transport on a special trailer pulled by a heavy truck. In this photo, a new MSSC is lowered aboard its trailer. The most vulnerable part of the MSSC is prominently shown in this photo -- the boarding steps. These steps were always getting crunched when the boat put into the beach to unload or load SEALs. Another weak point was the piano hinge for the forward-folding windshield. The welds tended to break and repair was difficult. The crew compartment was well protected by an inner and outer hull, Styrofoam insulation to absorb rocket shrapnel (and to act as flotation and sound deadening), a ceramic-backed steel-alloy armor plate, and thick Kevlar® flak curtains. [Photo: Tom Hawkins]

Below: An MSSC tied up at the Nha Be piers in late 1969 or early 1970. The boats in the back are MSBs (Mine Sweeping Boats) whose job it was to keep the Long Tau shipping channel to Saigon open and free of mines. The boats were made of wood and carried minimal firepower. Many people in Vietnam thought the guys that manned these boats were some of the bravest men they’d ever seen. The MSB was not fast enough to run from a fight and had neither the armament nor armor to stay and duke it out with the bad guys. [Photo: Tom Hawkins]

Above: Looking forward, the interior of the MSSC shows functional design. It is roomy for the SEALs and their gear (as well as the MST crew). The SEALs have rapid movement in and out over the bow, yet there is space for the gunners as well as good weapons locations for them. The center location allows the OIC to run the radios and navigate while the coxswain drives. The thick flak blankets that cover the interior armor are very prominent in this view. [Photo: Tom Hawkins]

Above: Interior of the MSSC looking aft shows a typical assortment of gear. The .50 caliber machine guns were installed amidships on all boats and a 7.62 NATO Mini-gun replaced the after mounted .50 machine gun from July and August 1970 onwards. C-ration cases and fresh water coolers are for extended operations. The 3,500-round magazine for the Mini-gun is directly below the bend in the belt feed chute leading to the gun. The spent case and link collection bag is directly below the gun. [Photo: Gary Hunt]

Below: A rear port quarter view of the MSSC as it pulls out on a SEAL operation. [Photo: Gary Hunt]

Above: The MSSC was a fast boat with a top speed of over 30 knots. Notice that the boarding steps are gone from this boat. The field expedient for the missing and broken steps was to hang a cargo net over the bow as shown here. This MSSC was based at Long Phu (Dung Island). [Photo: Bill Bremer]

Below: This Nam Can based LSSC is high and dry on the beach after the tide has gone out. The photo shows the water jet nozzles and cables that operate the reverse gates to good effect. [Photo: John Engstrom]

Above: By 1970, the LSSCs had removed their radar and radomes for increased interior room and protection from rocket shrapnel if the radome was hit. From the expression of the SEAL radioman on the bow, there’s some kind of communications glitch. Note that the SEALs are wearing Levi’s. The reason was the new camouflage pattern jackets and trousers had a problem. The trousers’ crotch would rip-out; the Levi’s were far more durable. Some SEALs also wore extra large panty hose underneath their Levi’s because any leaches they picked up would not stick to them. [Photo: Gary Hunt]

Below: Close-up of the Nam Can LSSC about September 1970. The post for the radar’s radome makes a convenient rack for the coxswain’s flak vest (big “lump” behind his head). [Photo: Bob Stoner]

Above: In January 1971, the LSSC at Nam Can took two B-40 rockets that killed the SEAL advisor and his LDNN interpreter and wounded many of the other MST and SEALs aboard. The reverse gate cables were severed by the rocket hits, but SEAL Don Crawford who took over the coxswain’s seat didn’t need reverse (fortunately). He was able to bring the boat back. The MST OIC and two other MST members required medical evacuation for their wounds. Don Crawford took this photo on the morning after the ambush of the night before. The two hits show up as large dents, one shows a perforation of the hull, and there are numerous shrapnel gouges. The LSSC looks the worse for wear after the ambush. [Photo: Don Crawford]

Other Craft – PACVs, LCMs, LCUs, and Air Boats

The Navy purchased its PACV (Patrol Air Cushion Vehicles) from the British Hovercraft Company as the Type BHC SR.N5. Seven hovercraft were converted by Bell Aero Systems to the SK-5 Model 7232 after re-equipping them with GE LM-100 gas turbine engines.

The Navy brought three PACV to Cat Lo as PACV Division 107, TF-116 (May 1966 to January 1967). Returned to Bell for overhaul, modification, and repair, they returned to Vietnam in 1968. This time they were assigned to Coastal Division 17 at Da Nang and Tan My until they returned stateside after the end of the Tet Offensive in September 1968.

Above: A Navy PACV comes ashore from USS GUNSTON HALL (LSD-5) in May 1967. PACVs also operated from USS TORTUGA (LSD-26) during their first deployment to Vietnam. [Photo: US Naval Historical Center]

Below: PACV No. 2 is shown at Moc Hoa in 1967. Notice the lack of outside decking for the crew or passengers. The decking was added before the PACVs second deployment in 1968. The forward access door is open. Although the PACV was fast and could cross all manner of terrain and water it was NOISY. No way could you sneak up on anyone. PACVs carried twin .50s above the pilothouse and M60 machine guns on either side (one is poking out of the second window aft of the standing crewman). [Photo: US Navy]

Above: PACV 3 at top speed over marshy ground somewhere near Da Nang or Tan My. Note the added deck on top of the hull that identifies a second tour modification. [Photo: US Navy]

Below: PACV 3 just after skirt inflation and before moving out. The heavy reinforcement for the post-modification external deck is very clearly shown. PACV units used revetments made of M8A1 steel mats to create a work and servicing area. An M8A1 mat was an interlocking, welded steel panel, 1.75 inches thick by 12 feet by 2 feet, weighing 144 pounds. A very durable servicing and work area could be put down in a very short period of time. PACV 3 is resting on M8A1 matting in this photo. [Photo: US Navy]

Above: A PACV demonstrates its amphibious capabilities at Da Nang during the second deployment to Vietnam in 1968. [Photo: Lee Wahler]

Below: The sole surviving PACV 4 (left) at the Bellingham International Maritime Museum, Bellingham, WA. When the PACVs retuned to the United States, some were transferred to the USCG. This may be one of those, based on the plexiglass bubble replacing the twin .50 machine gun mounting. The patch of PACV Div 107 (right). [Photos: BIMM, Lee Wahler]

The Army’s 9^th Infantry Division used three modified SK-5 ACVs based on a trials basis from 1968 to 1970. Army ACVs differed in physical arrangement from Navy PACVs.

The Army’s three improved SK-5 ACVs operated from its base at Dong Tam on the Mekong River. These craft arrived between January and May 1968 and operated from Dong Tam as the Air Cushion Unit (Provisional) until July 1969. When the 1^st and 2^nd Brigades of the 9^th Division rotated to the United States, the three ACVs were reassigned as the 39^th ACV Platoon, 3^rd Brigade in July 1969 until withdrawn from service in September 1970.

Above: One of the Army’s ACVs roaring down the My Tho River near Dong Tam at full speed. Army ACVs had a modified hull that incorporated a large deck for carrying troops, a larger cockpit than the Navy PACV, and two side-by-side .50 machine tubs. Performance was much the same as the Navy PACV. [Photo: Lee Wahler]

The Army ACVs had improvements over their Navy counterparts, although overall sizes remained about the same at 39 feet long, 24 feet wide, 16 feet high, and a range of 165 nautical miles. Army ACVs had more powerful engines than the Navy PACVs, a wider cockpit, two gun positions instead of one, and a flat deck on top of the lift skirt for troops. Although Army evaluation of the ACV was of much longer duration than the Navy’s, the vehicle was far too expensive to buy and maintain to justify expansion of its fleet.

A cushion of high-volume, low-pressure compressed air generated by a centrifugal lift fan supported both the Army ACV and Navy PACV. The lift fan created air pressure, contained by the side skirts, to lift the ACV off the ground. The ACV was almost frictionless in operation and could travel over land, swamps, or water at a speed of 75 knots. An ACV could clear rice paddy dikes and solid obstacles up to 3 feet high and negotiate a slope 6 feet high. The ACV could also force its way through tall grasses, fell small trees and brush, and navigate ditches and canals.

The same engine that powered the ACV lift fan also drove a 9-foot, three-bladed propeller. Twin rudders enabled the ACV to steer in much the same manner as an airboat. To maintain the air cushion, the ACV used canvas and rubber skirts to contain the compressed air.

Disposition of ACVs:

· Number 901 was written off in January 1970 when and ARVN soldier with full equipment was sucked through the lift fan. Number 901 was used as a source of spare parts for Numbers 902 and 903.

Above: ACV 901 in the salvage yard at Dong Tam. It was written-off in January 1970 and became a source of spares for 902 and 903. [Photo: US Army]

· Number 902 survived until September 1970, when the unit was disbanded.

Above: ACV 902 on alert status at Dong Tam. It was the only one of the three ACVs to mount an M5 40mm grenade launcher on the left front of the hull. The wide troop deck of the ACV is well shown in this shot. When the 39^th ACV Platoon stood down, 902 was taken to Ben Luc and probably scrapped there. [Photo: US Army]

· Number 903 was destroyed in combat in August 1970 and the unit commander killed. His successor commanded Number 902 for two months until the unit disbanded.

Above: ACV 903 up on jacks while her canvas and rubber skirt is replaced. The 903 was destroyed in action. [Photo: US Army]

Below: ACV 902 awaits her fate at the Ben Luc salvage yard sometime after the 39^th ACV platoon stand down in September 1970. [Photo: Ralph Christopher]

Perhaps no other amphibious craft had more modifications done to it during the Vietnam War than the humble Landing Craft Mechanized (LCM) Mark 6. The Mk 6 was a 56-foot long landing craft that had been designed to land M4 Sherman tanks in World War 2. The Mk 6 was identical to the Mk 3, its 50-foot long predecessor. Unless both boats were seen side-by-side, they were very difficult to tell apart. The Mk 6 was 14 feet wide and weighed 65 tons (loaded). It had two GM 6-71 diesel engines driving two props for a top speed of 10 knots. Useful load was 34 tons of cargo or 80 troops.

The LCM Mk 6 was used as the basis of many specialized conversions for the riverine warfare environment. The HSSC versions done by SEAL Team ONE and Boat Support Unit ONE are only two examples. Many more conversions were done and most of those boats were attached to TF-117, the Mobile Riverine Force. The MRF is described in Part 3 of this series.

Above: A drawing showing the arrangement of the LCM Mk 6.

Below: A scale drawing of the LCM Mk 8. [Drawings: US Navy]

The LCM Mk 8 was a much longer and heavier craft of post-Korean War design. The Mk 8 was designed to transport the M48 or M60 tank that was much larger and 40 percent heavier than the WW2 Sherman tank. The Mk 8 had two 12V-71 diesels driving two props, was 74 feet long and 21 feet wide, weighed 105 tons (loaded), and carried 52 tons of cargo or 200 troops. The Mk 8 was widely used by both the Navy and the Army in Vietnam to carry all manner of cargo. The Army’s Transportation Corps ran Army LCMs.

Below: A Navy drawing of the LCM Mk 3 showing the features of the boat; the Mk 6 is identical except it is 6 feet longer. The LCM-6 or “Mike 6” is still used by the Navy although its primary role of beach assault has been superseded by much larger and faster craft. [Drawing: US Navy]

Below: A factory fresh LCM-6. Note the lack of identifying unit numbers and codes that will be added when it is assigned to a ship or unit. [Photo: US Navy]

Above: An LCM-8 coming ashore through the surf with a load of vehicles. The “CH” and “KA 113-2” identify this as the number 2 LCM-8 from the USS CHARLESTON (LKA-113). [Photo: US Navy]

Below: An Army LCM-8 in Vietnam. Army crews lived aboard their craft and so they enlarged the conning stations into bunkrooms using 2x4s and corrugated sheet metal and tarpaper for the standard crew of 4 or 5 men. In this shot, a UH-1D medical evacuation helicopter is taking off a casualty. Armament was two .50 machineguns. [Photo: Lee Wahler]

Originally called the Landing Craft Tank (LCT) the vessels of the 1466-class were reclassified as LCUs (Landing Craft Utility). The LCT/LCU had triple the cargo capacity of the LCM-8. The “U-boats” did a lot of supply hauling in Vietnam and their work went largely unnoticed. The modified LCT-5/LCU-1466 class was 119 feet long, had a beam of 34 feet, and drew 6 feet of water. Its speed was 10 knots and it carried a crew of 14. Cargo capacity was 150 tons and it weighted 360 tons (loaded). Armament consisted of three twin 20mm guns or twin .50 machine guns. Propulsion was by three diesels turning three propellers. Range was roughly 700 nautical miles at 7 knots. The USN transferred sixteen LCUs to the VNN by January 1971.

Above: LCU-1475 at Da Nang loading a cargo of ammunition bound for Hue in 1969. LCU-1475 is a Mk 5 LCT design with one ramp. YFU-60 (ex-LCU-851) is moored alongside. This is a Mk 6 LCT design with an offset pilothouse and both a stern and a bow ramp for roll-on and roll-off cargo. LCU-1475 was transferred to the VNN as HQ-540 by January 1971. [Photo: Tom Lanagan]

Above: A good starboard side shot of LCU-1493 moving cargo on the Perfume River in South Vietnam about 1969. Like her sister, LCU-1493 was transferred to the VNN as HQ-543 by January 1971. [Photo: Joe Criscione]

Below: One of the stranger craft was this swamp boat or airboat. Army SOG advisors and Chinese mercenaries ran these craft in the Plain of Reeds, a vast Everglades-like swamp northwest of My Tho. [Photo: Don Basallion]

R2 End of Part 2.