NASTY! The inside story of Operation 34A and the Nasty-class PT boats – and the crews that manned them during the Viet-Nam War

Most Americans consider that our involvement in the Vietnamese War began with the Tonkin Gulf incident. The fact is our involvement began almost immediately following the 1954 Geneva Peace Accords that divided the country at the 17th parallel. The Pentagon Papers leaked some information, but the whole story of this operation is only now becoming known. Immediately following the Accords, CIA Director Allen Dulles sent Air Force Colonel Edward Lansdale to Viet-Nam as Deputy Director of the Office of Special Operation with orders to implement clandestine operations against the North. Highly experienced in such operations, in the 1950s Lansdale performed similar duties for President Magasasay ridding the Philippines of Huk Communists.

Lansdale recruited and trained Vietnamese civilians to carry out the initial counter-insurgency operations against North Viet-Nam. Lansdale relied on a variety of ethnic Vietnamese crews to accomplish this mission including Nung and other minorities that came from areas close to the Chinese border. For security reasons, Lansdale used Saipan as a training center. Later, the CIA borrowed trained counter-insurgency operatives from Taiwan for commando raids into North Viet-Nam. Early operations used native junks since they blended into the fishing boats off the North Vietnamese waters. These operations continued over the years, some highly successful while others were less so, resulting in the complete loss of some crews. The code name for these operations was NAUTILUS after the mysterious submarine from Jules Verne’s 20,000 Leagues Under The Sea. Missions consisted of inserting spies recruited by the CIA and commando raids conducted by Republic of Viet-Nam frogmen. As the NVN Navy improved intelligence g athering capabilities, the routes used by NAUTILUS missions became well known and the junks soon lost their advantage of blending in. The NVN simply waited for the junks to cross the 17th parallel. The junk’s slow speed and weak firepower became too much of a disadvantage against North Viet-Nam’s heavily armed Swatow and P-4 gunboats.

In July 1962, the CIA and the Department of Defense determined that the CIA did not have the operational capability and capacity to effectively carry out the mission and determined that the DOD should have operational control. Admiral Harry Flelt, Commander in Chief, Pacific, analyzed the situation and recommended that PT boats and frogmen be used to carry out the mission. President Kennedy, himself a WWII PT boat commander, liked the idea and approved its immediate implementation. On 1 January 1963 the Military Assistance Command, Viet-Nam Special Operations Group (MACV-SOG) assumed the responsibility for operations.

Operations Plan 34A

In May 1963, the Joint Chiefs of Staff directed Admiral Flelt to prepare a plan to support the RVN Navy effort to carry out special operations in North Viet-Nam. On 14 August the JCS approved the final plan that became OPLAN 34-63. Slight adjustments were again made and approved on 9 Sep 63. Before fully implemented, a coup d’etat against President Ngo Dinh Diem took place on 3 Nov. Despite the command confusion, commando raids continued under OPLAN 34-63. By December MACV-SOG became disappointed with performance and sought ARVN military participation. A new plan, known as OPLAN 34A was prepared that included ARVN with U.S. Navy support and was approved by JCS on 15 Dec. Secretary of Defense McNamara and President Johnson wanted to deliver a strong message to North Viet-Nam that the U.S. would not accept the Communist invasion of the RVN. The main objective was to combine the attacks against the North with diplomatic pressure to warn the North to cease their infiltration in Laos and RVN. Thus, the United States entered into a new phase of the clandestine operations against the North.

To support this operation, the U.S. Navy set up a base in Da Nang consisting of SEALS, U.S. Marine intelligence officers and other specialists experienced in guerrilla operations. Two PT boat crews along with necessary maintenance crews were sent to train Vietnamese crews in PT boat operations and methods to use them in commando raids. On 21 Jan 64, JCS approved the implementation of the first phase of OPLAN 34A. The maritime section of OPLAN 34A had the main objective of conducting operations on the sea routes and to engage in psychological warfare against North Viet-Nam. The JCS maintained tight control over operational planning leaving the details of completing the plan to MACV-SOG personnel.

The organizational structure that specialized in running the coastal commando operations consisted of the Vietnamese Navy Coastal Security Service comprised of VN SEALS and boat crews and technical specialists. All Vietnamese SEAL teams and boat crews were recruited from the brightest and best of the VN Navy with superior service records. In addition, a small number of VN Army specialists were recruited and trained in SEAL tactics. The junks were rapidly replaced with Nasty-class PT boats. At that time, the Nasty was considered the best and most modern PT boat in the world.

Tonkin Gulf incident

By early 1964, operations using the newly arrived PT boats were in full swing with excellent success. On 30 Jul 64, impressed with the operational success, the JCS ordered to triple the August schedule over that of July. This was a six-fold increase over the June schedule. On the night of 30 Jul, the more aggressive schedule involved a nighttime raid on Hon Me and Hon Nieu islands off Thanh Hoa coast. This was a four-boat raid involving PTF-2, PTF-3, PTF-5 and PTF-6. (PTF-2 was one of the gasoline-powered boats; the others were Nastys). At midnight, the four boats split up and headed for their respective objectives. At Hon Me, a fuselage of heavy machine gun bullets met PTF-3 and PTF-6 causing heavy damage to the bow of PTF-6 and wounding four crewmen. Suddenly, a crewman sighted a Swatow patrol boat mooring near the island. With insufficient time to get a SEAL team ashore to blow up the target, the crew blasted a water tower and several military buildings with 40mm and 20mm gunfire. Caught in the glare of an illumination flare fired by the Swatow, the PTFs continued to pour fire into the targets. In less than 25 minutes, the attack was over. It was now 30 minutes into 1 Aug. Both boats sped away at 55 knots, easily outdistancing the Swatow only making about 45 knots.

At Hon Nieu, PTF-2 and PTF-5 had better luck. They approached unnoticed and hammered a communications tower silhouetted in the moonlight. Only light machine gun fire was returned with no damage. After 45 minutes of pounding the tower and other targets, both boats raced back to Da Nang. North Viet-Nam lodged a complaint with the International Control Commission; the United States denied involvement. In response, the North Vietnamese commenced a buildup of their naval presence and shifted about one-third of their 50 P-4 and Swatow gunboats from Hai Phong to that area. General Westmoreland recognized that the successful 34A operations were responsible for this response.

At about the same time as the implementation of OPLAN 34A, the Navy began Desoto patrols along the coast that were designed to eavesdrop on communications from North Viet-Nam. These patrols were conducted by American tin cans that were careful to stay in international waters, at least four miles off shore in the case of North Viet-Nam. General Westmoreland and Admiral Sharp, Pacific Fleet Commander-in-Chief, had discussed using the Desoto patrols to assist in the direct conduct of 34A operations; however, this was abandoned to preserve the plausible deniability of U.S. involvement. Nevertheless, in July 1964, Westmoreland had requested that Desoto monitor the upcoming 34A operations in case they were needed for support.

Two days following the attacks on Hon Nieu and Hon Me, at 1600 on 2 Aug, frustrated with its inability to interdict the Nasty boats, North Viet-Nam launched a torpedo attack against USS Maddox (DD 731) using four Soviet torpedo boats. Maddox, supported by aircraft from USS Ticonderoga (CVA 14), shot up the attacking boats leaving one boat dead in the water. The battle was over in 22 minutes. Maddox took machine gun rounds from a North Vietnamese PT boat, but steamed out of the area without further damage and no loss of life. The North Vietnamese had naturally connected the Desoto destroyers with the events of late July and early August since Maddox was steaming off the coast of Hon Me Island at the time.

Undeterred by the events of 2 Aug, the maritime operations from Da Nang launched a four-boat 34A operation on 3 Aug. The objective was to bombard a radar station at Vinh Son and a security post on the banks of the Ron River; both about 90 miles north of the 17th parallel. PTF-1, PTF-2, PTF-5 and PTF6 were involved. After a successful attack, the PT boats kicked into flank speed of 50-plus knots easily outdistancing pursuing enemy Swatows. Knocking out the radar station blinded North Viet-Nam, contributing to their confusion.

On 4 Aug, Maddox and USS Turner Joy (DD 951) reported that they were involved in an attack. The next day planes from Ticonderoga and USS Constellation (CVA 64) struck an oil storage site in North Viet-Nam and destroyed coastal vessels. On 7 Aug, the U.S. Congress passed the Tonkin Gulf Resolution with overwhelming support. It is well known now that the 4 Aug attack did not actually occur. This series of events permanently disrupted attempts by President Johnson to send a message to the North Vietnamese government through the Canadian delegation to stop its war against the South, thus setting the course of action for the next 10 years.

The ICC immediately headed for Da Nang to investigate the PT boat base. In the meantime, the Navy relocated the PT boats south to Cam Ranh Bay where they lay low until the ICC investigation was over; a week later they were back in Da Nang, the crew having spent the week camping out on a small pier. Back in Washington, President Johnson ordered a halt in 34A operations to avoid any ambiguous message. By now, the veil of secrecy as to the location of the PT boats was thin. Ambassador Maxwell Taylor, in Saigon, objected to the halt of operations. Following the Tonkin Gulf Resolution, the attacks again commenced in earnest.

Why the Nasty-class PT boat?

The search for a boat dates back to 1959 when the Navy was looking to replace the aging WWII torpedo boats. The top choice was the 80-foot Nasty-class patrol boat used with considerable success by the Norwegian Navy since 1957. Built in Norway, the boat had two British-built supercharged diesel engines delivering 3,100 shaft horsepower and could reach speeds of 44 knots fully loaded and speeds of over 50 knots after burning off some fuel. The cruising range could extend to about 1,000 miles at a speed of 20 knots. The Navy ordered 16 Nasty-class boats and classified them as Patrol Torpedo, Fast, or PTF.

To fill in the demand before the Nastys arrived, Navy planners found two old WWII vintage PT boats. These boats were powered by Packard engines running on gasoline, but proved unreliable in this mission due to engine problems and noise. In fact, the engines were difficult to start at times and this proved to be a serious weakness when inserted into North Viet-Nam waters and being surprised by a Russian-made P-4 or Swatow patrol boat. By the end of 1965, when enough Nastys became available, the gasoline boats were replaced and used for target practice.

The firepower of the Nasty was significant, consisting of a 40mm gun on the aft deck and two 20mm guns, one on the port and one on the starboard side. An 81mm mortar with a 50-caliber machine gun mounted piggyback was placed forward of the bridge. On some missions, the crews carried a 57mm recoilless rifle for additional firepower.

In total, 16 Nasty boats saw service in Viet-Nam. As the demand for 34A operations increased and some were lost in action, an American company, Trumpy Boat Company, commenced building a knock-off of the Nasty called the Osprey. The Ospreys were of aluminum construction while the Nastys were laminated wood. The flexibility of the wooden construction actually proved to be superior and some of the Osprey design developed stress cracks in battle conditions and at flank speed in rough seas.

Action North

Many of the missions north of the 17th were simply milk runs with a continuous threat of meeting up with shore bombardment, attack by air or an attack by P-4 or Swatow gunboats. In addition, the North Vietnamese sometimes used suicide junks to try to sink a Nasty. During the length of the war, only one boat was lost to direct enemy action when a North Vietnamese biplane dropped a homemade bomb that hit PTF-9 on the fantail, flooding the engine room. Other boats were lost when they ran aground racing south following an attack or while being chased by an enemy gunboat.

Direct action against the Russian-made P-4 and Swatow gunboats was always one-sided. The Nasty was a superior boat with superior crews and superior firepower. In most cases, the North Vietnamese simply avoided direct combat or faked engine trouble to avoid a fight, or they radioed back that the Nasty was pulling away out of gunfire range. The after-action report by some aggressive Nasty officers sets the tone for the entire war:

On the night of 19-20 Feb 71, four PTFs were near Hon Nieu observing and photographing Chinese shipping. Suddenly the boats were attacked by a North Vietnamese P-4, which was engaged and easily sunk. Mission compromised; the four PTFs headed south and within an hour were engaged by a P-4 and a Swatow. The PTFs left the attacking boats heavily damaged and continued south. Between Hon Gio Island and the coast, a P-4 torpedo boat and a Shanghai-class gunboat again attacked them. The PTFs left the attacking boats damaged and sped back to Da Nang at 55 knots, undamaged and with one KIA.

During the duration of OPLAN 34A, the Nastys sank the majority of the P-4 boats.


OPLAN 34A missions were of a strategic nature primarily involving clandestine psychological warfare and secondarily commando raids to destroy military targets. Psychological operations included tax extraction from fishing boats, propaganda distribution using the 81mm mortar and other operations creating havoc behind enemy lines. Some included taking snatches to Cu Lao Cham Island offshore from Da Nang where they were well fed and led to believe that they actually lived in a secret liberation zone of the “Sacred Sword of Patriotic League” located in North Viet-Nam. Later they were taken back to the north, plump and well fed, with the expectation that they would spread the story of the lifestyle outside of communism. Most of the psychological operations occurred north of the 18th parallel in more densely populated areas. Additionally, psyc-operations included dropping radios with a fixed frequency set on a CIA-run station.

Vietnamese SEAL teams conducted raids and shore bombardment missions designed to destroy specific targets and to extract snatches. Military snatches in these missions were also carried to an offshore island for interrogation and perhaps reeducation.

The following first-hand account describes the typical psychological operation:

“During 1967, we undertook a special psychological warfare program. We captured more than 300 fishermen in a three-month period. We took two individuals from every village. After delivering them to Cu Lao Cham we made sure that they were well fed. Each person ate a half chicken every day and after three months, was plump and had a healthy complexion. We took each back to their hometown to see what the reaction would be both locally and to the regime. It came as no surprise to us during the next six months that when we tried to capture the same individuals, they were nowhere to be found. After almost nine months had passed, we finally captured one fellow who signed: ‘You folks hurt us. When you released us, the local government officials noticed that we were fat so they put us in the thought reform camps and just released us’.”


The Vietnamese Navy recruited boat officers from the most motivated and highest ranked graduates of the Naval Academy. Likewise, boat crews came from the most capable and experienced seamen. Motivation and esprit de corps were always high among the crews and MACV-SOG maintained morale by supplementing their pay with an extra payment and special rations for each trip north. As an example of the high morale, crewmen always volunteered for difficult missions in addition to their own schedules.

There were rumors that American personnel were on board PTFs on missions to the north. This is not true, at least from 1965 to 1970 when the authors were with the PTFs in Da Nang.

Over the roughly eight years in operation, OPLAN 34A sent over 1,000 missions into waters off North Viet-Nam. Nearly all missions were successful and achieved their primary or secondary objective. Few were a complete bust and none failed because of poor leadership or lack of skill. As an example of leadership and seamanship, the Vietnamese crews had less than 40 casualties out of the thousands of individual missions. The single worst skirmish was a blue-on-blue event with one boat losing two officers. Clearly, the crews that manned the Nastys were the best that Viet-Nam had to offer and they lived up to the highest standards.

Editor’s note: Jack Jennings served with boat Support Unit 1 from 1965-66. He now resides in Dallas, TX, and can be reached by e-mail at Tran Do Cam served for five years as Executive Officer and Commanding Officer of PTFs. He now resides in Austin, TX, and can be reached by e-mail at