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Market Time (U)


1401 Wilson Boulevard
Arlington, Virginia 22209

Operations Evaluation Group

By: Judith C. Erdheim

September 1975

Prepared for:
Office of Naval Research
Department of the Navy
Washington, D.C. 20350

Office of Chief of Naval Operations (Op03)
Department of the Navy
Washington, D.C. 20380

Table of Contents

Foreword iii
Summary iv

Background 1
  NVN Resupply System 1
    Group 125 Infiltration 1
    WBLC Infiltration 2
    Coastal Transshipment 3
    Other Seaborne Resupply 3
Pre-Market Time Vietnamese Coastal Surveillance 4
First Trawler Infiltration Era: February 1956-March 1968 8
  Market Time under the Seventh Fleet and NAG 8
    Planning the Operation 8
    Assignment of Forces 8
    Building Up an Intelligence Capability 16
    TF 115 Established 18
    Setting Up Barriers and Increasing Force Levels 18
    Search Tactics 21
    Arrival of PCFs 22
    Enemy activity 23
  Market Time under ComNavForV 24
    Multitrawler Infiltration Attempt Following Tet 26
    Market Time Status at NavForV Takeover 27
    Secondary Market Time Missions 28
    Naval Gunfire Support (NGFS) 28
    Psychological Operations 28
    Coastal Surveillance Operations 29
    Turnover of Market Time Assets to VNN 31
Pause in Trawler Infiltration Activity: March 1968 to August 1969 34
  Enemy Resupply 34
  Coastal Surveillance Operations 34
    CTF 115 Becomes More Aggressive 37
Second trawler Infiltration Era: August 1969-April 1972 40
  Increase in Seaborne Infiltration Attempts 40
    NVN Coordinating Units 40
    Progress of Vietnamization 41
    Penetration Exercises 42
    Covert Surveillance 44
    SL-8 Trawlers 44
    Other Enemy Activity 45
    Cloud Concept 45
    New Air Patrols 48
    Photoreconnaissance 50
    Change in Priorities 50
    Enemy Seaborne Infiltration and Transshipment Activity 50
    Status of Vietnamization 52
Final Stage: May 1972-January 1973 54
  Progress of Vietnamization 54
Conclusions 56
Bibliography 57
Appendix A - Characteristics of VNN PCE and PGM A-1--A-2
Appendix B - Characteristics of Surface Craft Assigned to Market Time B-1--B-6
Appendix C - Characteristics of VP Aircraft assigned to Market Time C-1--C-3
Appendix D - Market Time Surface Craft Force Levels D-1--D-5
Appendix E - Market Time Aircraft Force Levels E-1--E-3
Appendix F - Group 15 Inventory and Trawler Characteristics F-1--F-3
Appendix G - Trawler Infiltration Attempts G-1--G-3
Appendix H - Suspected Merchant Ship Smuggling on Mekong River H-1--H-4
Appendix I - Rules of Engagement I-1--I-15
Appendix J - Major Findings from Market Time Questionnaire J-1--J-2



In addition to the documents listed in the bibliography appearing at the end of the main text, this research contribution is based on interviews and correspondence with Market Time participants; responses to a questionnaire prepared by the author; COMNAVFORFIVE, CINCPACFLT, CINCPAC, COMSEVENTHFLT, and CTF 115 message traffic; fact sheets; command histories; NAVFORFIVE in-house working papers, memoranda, and drafts of briefings and studies; and information provided by CIA and DIA.

Most of this information (except that provided by the intelligence agencies) can be found in the Vietnam Command Files and the COMNAVFORFIVE Provenance Files at the Naval History Division Archives. The author expresses her appreciation to Oscar Fitzgerald of the Naval History Division for his patience and help in using these files. The author, of course, assumes full responsibility for her interpretations of these documents.



Market Time was established in March 1965 as a coastal surveillance operation to prevent seaborne infiltration of supplies from North Vietnam (NVN) into South Vietnam (SVN). The objectives of the operation were soon expanded to include prevention of coastal transshipment of enemy supplies within SVN.

This research contribution summarizes Market Time in terms of the threat, the U.S. Navy-Coast Guard/Vietnamese Navy (VNN) response to the threat, limitations that might have affected this response, and the operation's effects on the enemy. The discussion includes the enemy's need for re-supply, possible infiltration routes, the potential for seaborne infiltration, and known infiltration. Secondary missions of Market Time such as naval gunfire support (NGFS) are examined only as they affected Market Time's coastal surveillance mission.

There were several methods of seaborne infiltration facing market Time. Trawlers under the control of NVN Naval Transportation Group 125 would either infiltrate directly over a beach or off-load onto sampans and junks several miles offshore. Trawlers were capable of carrying 100 to 400 tons of cargo. Waterborne logistic craft (WBLC) infiltrated below the 17th parallel to Military Region (MR)-1 of SVN (Figure 1); and enemy trans-shipment was done by small boats within SVN coastal waters. These small craft would mingle with the thousands of similar boats used for fishing and transportation along the coast of SVN.

Major Phases of Trawler Infiltration Activity

Enemy seaborne infiltration as perceived by U.S. forces can be divided into five major phases of trawler infiltration activity:

  • Pre-Market Time infiltration (1962-1965).

  • First trawler infiltration era (February 1965-March 1968).

  • Pause in trawler infiltration attempts (March 1968-August 1969).

  • Second trawler infiltration era (August 1969-April 1972).

  • Wrap-up (April 1972-January 1973 cease-fire).

Knowledge of the enemy's seaborne infiltration activity before March 1965 is very sketchy. Enough is known, however, to establish the Mekong Delta as the focus of pre-Market Time seaborne infiltration.




First Trawler Infiltration Era

The first infiltration era dates back to the February 1965 discovery of a trawler that had successfully infiltrated Vung Ro Bay. During this era, trawler infiltration attempts focused on MR-1 and--2 as well as the VC-infested Delta region in southern SVN (MR-4). There had been an influx of North Vietnamese army (NVA) main forces into MR-1 and--2 during 1965, and attempts were made to resupply those troops from the sea. These attempts were crisis-oriented; 8 of 12 trawlers between March 1965 and March 1968 approached the coast even through they must have realized they were under surveillance. All were either totally or partially destroyed.

The North Vietnamese attempt to land four trawlers simultaneously in February 1968, after the Tet offensive, was the best example that the enemy was responding to a crisis by attempting to resupply his forces rapidly from the sea. Market Time forces destroyed three of the trawlers; the fourth aborted its mission. Large amounts of medical supplies were salvaged from one of the destroyed trawlers.

Hiatus in Detected Trawler Infiltration Attempts

After the unsuccessful four-trawler effort in March 1968, no trawler infiltration attempt was detected by Market Time for a year and a half. By 1968, Market Time was considered by Commander, Naval Forces Vietnam (COMNAVFORFIVE) and Commander, Military Assistance Command, Vietnam (COMUSMACFIVE) to be an effective deterrent against seaborne infiltration. It could have been that the disastrous March attempt to land four trawlers had forced the enemy to reconsider alternate resupply routes.

During this period, the North Vietnamese were using Cambodia as a base area to resupply MR-3 and -4 and southern MR-2 in SVN. From October 1966 through July 1969, there were 11,000 to 19,400 tons of military supplies delivered by Chinese ships to Sihanoukville destined for VC and NVA elements. Although direct delivery to SVN by sea would have been far simpler than the Cambodian route, Sihanoukville was open while Market Time hindered seaborne infiltration. The VC/NVA therefore turned to Cambodia as a resupply route to southern SVN.

Although many Market Time participants felt that no trawler evaded the barriers during that year-and-a-half hiatus, later information suggests that it would have been possible for an infiltrator to evade detection. But there is no intelligence information suggesting that any such infiltration occurred between March 1968 and August 1969. In any event, with free access to Cambodia, there was no critical need for the enemy to use seaborne infiltration for southern SVN. MR-1 and -2 wee taken care of by the overland route (Ho Chi Minh Trail), which had been expanded.


Second Trawler Infiltration Era

The second trawler infiltration era began with the detection of an NVN trawler in August 1969. There were to be 38 detected trawler infiltration attempts during this era, which ended with the destruction of a trawler in international waters on 24 April 1972. Two of the 38 attempts were discovered to have been successful.

During the Summer of 1969, Prince Sihanouk of Cambodia placed an embargo on shipping arms through his country to the VC/NVA forces in SVN. Although the embargo was temporarily lifted, it was reimposed permanently by late 1969. Sihanouk's ouster in March 1970 and U.S./SVN cross-border operations into Cambodia that Spring permanently halted communist shipments through Sihanoukville. The communists then turned to the sea once more to resupply their forces in southern SVN.

This second era brought several trawler infiltration tactics that had not been observed during the first era. From 1969 on, the trawlers generally aborted their missions when they realized they were under surveillance; previously, most of them had tried to complete their missions. Group 125 had little to lose when its trawlers simply returned home instead of closing the coast under surveillance to what was often a future and fatal conclusion.

A new type of trawler, the SL-8, was detected in an infiltration attempt during February 1971. This trawler was larger and more seaworthy than any used before. It could carry 400 tons of cargo, compared with the 100 tons that trawlers previously detected could carry.

NVN trawlers evidently had begun to use a new route for seaborne infiltration in December 1971.Until then, the trawlers presumably had to transit the gap between the Dangerous Ground and the SVN coast.The new route took the trawlers through the Palawan Passage and back to SVN, circumventing the established Market Time air patrol areas. About the same time the new trawler route was discovered, it seemed that the North Vietnamese were trying to flood Market Time barriers by sending down three to four ships within 10 to 25 days. This tactic had not been observed since February 1968.


After the VNN destroyed a trawler in international waters in April 1973, no other infiltrating trawlers were detected. There are two possible explanations. One is that the destruction of a trawler on the high seas could have convinced the North Vietnamese that they would no longer have the option of aborting before entering SVN's waters once under surveillance. The second explanation may be that Group 125 trawlers could have been trapped in Haiphong during operation Pocket Money, the May 1972 mining of ports in NVN. Although there was evidence suggesting the Group 125 trawlers used Hainan Island, it is not clear whether its facilities and assets had been moved form Haiphong before Pocket Money.


In mid-1972, Group 125 was eliminated.

NVN established a new seaborne infiltration group, which used smaller fishing vessels purchased and registered in SVN.

Market Time Operations

At first, Market Time was under the control of COMSEVENTHFLEET, but the operation was soon transferred to the Naval Advisory Group (NAG), subordinate to MACV. NAVFORFIVE was established as a separate command in April 1966, with Task Force 115 delegated responsibility for Market Time.

Five Coastal Surveillance Centers were established: Danang, Qui Nhon, Nha Trang, Vung Tau, and An Thoi. These centers coordinated coastal surveillance activities of the VNN and U.S. Navy. CTF 115 originally operated out of Saigon; he later moved to Cam Ranh Bay.

For most of the operation, U.S. forces performed coastal surveillance with three barriers - air, outer surface, and inner surface. VNN junks and patrol craft helped U.S. forces, but the did no become an integral part of the operation until Vietnamization.

Air Barrier

The air barrier was first flown by P-2s, P-3s, and P-5s. During the operation, VP aircraft flew from a seadrome and from five different bases (two in SVN, one in Thailand, and two in the Philippines). Apparently, the personnel ceiling in SVN was responsible for the out-of-country bases. By January 1969, P-2s and P-5s had been phased out of Market Time, and P-3s alone flew the patrols.

During the first few years of the operation, Market Time patrols experimented with many different tracks. The tracks most generally flown covered the southern part of SVN to Vung Tau and the sector fro Vung Tau north. One leg of the track was flown over the coast, and other 40 to 60 n. mi. offshore and parallel to the coast. In 1967, the patrols were flown off the northern and central southern sectors of SVN parallel to and 70 n. mi. from the coast, with a permitted deviation of 50 n. mi. on either side of the track. Every contract was to be investigated.

By January 1969, one P-3 flew a barrier from the demilitarized zone (DMZ) to Phu Quoc, 70 n. mi. offshore. A P-3 could cover the entire coast in a single sortie. But after a series of penetration exercises conducted by Seventh Fleet ships, the barrier was recognized as being susceptible to infiltration, for two reasons. First, the fixed tracks of the P-3s could be taken advantage of by an informed infiltrator. Second, the P-3s could not identify contacts at night. New daytime-only patrols wee instituted. The patrols were extended eastward and randomized so that an informed infiltrator could not penetrate the barrier; flight paths were also shifted back and forth to 20 n. mi. on either side of the tracks.


(U) Along with the new patrols came a change in the Market Time concept of operations. Until 1970, Market Time practiced overt surveillance of trawlers; they were tracked until the Market Time units were sure the mission had been aborted. In the second trawler infiltration era, this practice of overt surveillance might have encouraged more attempts. Trawler crews knew that there would be nothing to lose if they were to abort before reaching SVN waters (12 n. mi. offshore) since the Market Time Rules of Engagement (ROE) prohibited VP aircraft from engaging trawlers in international waters. This meant trawlers could attempt infiltration and break off when they came under surveillance. COMNAVFORFIVE analysts concluded that the Market Time practice of overt surveillance of enemy trawlers did not damage the enemy while it tied up U.S. assets.

(U) By the end of 1970 Market Time forces were directed to maintain covert surveillance whenever possible. The fist time covert surveillance was successfully practiced (during November 1970), a trawler was destroyed.

(U) In 1971, the air patrols were changed in reaction to intelligence suggesting that MR-4 was the target of trawler infiltration attempts. The trawlers probably passed through the choke point between the Dangerous Ground and the SVN coast. The new patrol, an "advancing" patrol, was based on aknowledge of trawler capabilities and destination. If the information were correct, trawlers would not be able to evade the advancing patrol. (U) There was a change in emphasis for Market Time air patrols during 1971. Instead of investigating every contact, the patrols began to concentrate on the smaller contacts. It was the smaller contacts that would prove to Group 125 trawlers; the primary mission of Market Time was to prevent infiltration by these trawlers, not to track merchant ships.

(S) There were other changes in priorities affecting Market Time during 1971. Information from photoreconnaissance flights over NVN and Hainan was provided to Market Time. Every time these photos indicated that a Group 125 trawler had left its home part, the information was passed to a U.S. submarine off the Chinese coast. If the trawler passed through the Hainan Straits and headed south, the submarine would contact Market Time aircraft. The submarine also tracked the SL-4 destroyed by the VNN in April 1972.

(C) In February 1972, after it had been determined that trawlers were transiting the Palawan Passage enroute to SVN, an advancing patrol was established to cover that passage and the Dangerous Ground. Adequate intelligence had provided an input to the development of the Market Time air patrols.


Surface Barriers

The outer surface barrier was patrolled by deeper-draft vessels - DERs, MSOs, and MSCs and later, WHECs and PGs. Once the outer barrier was divided into nine large sectors in 1965, no major change was made for the remainder of the operation.

Vietnamization brought a winding down of U. S. Navy activity, and there were fewer sectors covered as the outer barrier came under VNN control. The area covered by the ships varied over the years from 10-15 to 12-40 n. mi. offshore.

The inner surface barrier was patrolled by shallow-draft PCFs and WPBs from inshore to the area manned by outer barrier ships. U. S. Navy/Coast Guard participation in the inner barrier peaked at 84 PCFs and 26 WPBs. The boats were assigned inshore areas of operation within the nine sectors.

Patrols suffered at the tip of An Xuyen Province because support bases for inner-barrier craft were too widespread. A major improvement in coverage of this area came during Vietnamization, when a base was established at Nam Can in the heart of VC controlled territory at the tip of An Xuyen Province.

A major change in the concept of the inner barrier came in 1971 after the South Vietnamese had assumed responsibility for the inner barrier for several months. High-threat areas of the coast wee pinpointed and the inner-barrier craft formed into task units. The objective to the task units or "Clouds," was to change the former fixed patrols and concentrate forces in areas that were prime targets for transshipment or infiltration. Single boats were left to patrol low threat areas.

Sea Lords Induces Change

A major change in the concept of operations for the task forces under COMNAVFORFIVE included Market Time in 1968. The fairly passive patrols had previously been restricted to the coast. In 1968, patrols became more aggressive as PCFs became part of the Sea Lords operation to clear MR-4 waterways of VC. PCFs participated in raids up the canals and rivers of the Delta. Increased gunfire support was emphasized for both inner and outer barrier craft.

Vietnamization Induces Changes

As the U. S. Navy removed some of its Market Time assets, a replacement had to be found for the P-3s, whose detection capability had been essential to the operation. A coastal radar system was developed, and by mid-1972, 15 coastal stations and a radar ship had been turned over to SVN. But these stations lacked the identification capability of the P-3s, providing surface forces reaction times of only hours instead of the two to three days provided by the P-3s.


The radar system served as the impetus for development of the "Cloud" concept. This concept was designed to meet the need for a strong inner barrier reaction force, since by the time a contact was detected by the radar system and the information disseminated, it could well be the job of inner barrier assets to intercept the infiltrator. Task units might be able to handle an infiltrating trawler, but individual boats certainly did not have adequate firepower.

By December 1972, VNN had taken over the inner barrier, the outer barrier, and the coastal radar system, and CTF-115 was dissolved. An adequate replacement had not yet been found for U.S. Navy VP aircraft, which were still flying Market Time surveillance missions at the time of the cease-fire. The radar system could not provide the same reaction time and coverage that the P-3s did. The aircraft never were scheduled to be turned over to the South Vietnamese.




NVN has been organized to direct infiltration into SVN since 1959. During that year, VC needs for out-of-country resupply in SVN began to increase. Possible infiltration routes were the Ho Chi Minh Trail (first upgraded in 1959), Cambodia (used at least since 1964), and the sea.

Seaborne infiltration was recognized as a possible means of resupply as early as 1961. Cargo that took 170 days overland to reach the VC/NVA in SVN reached them in a few days by sea with far less manpower expended.

There were several methods of seaborne infiltration that Market Time ultimately had to face. In the early 1960s, trawlers capable of carrying 60 to 100 tons of supplies infiltrated directly to the beach or offloaded onto smaller craft several miles offshore. During Market Time, trawlers capable of carrying 100 to 400 tons of cargo appeared as infiltrators. Smaller craft infiltrated below the 17th parallel to MR-1, or performed resupply functions as coastal transshippers within SVN.

Group 125 Infiltration

Trawlers under the operational control of NVN 125th Naval Transportation Group had been resupplying the VC in SVN at least since 1962. The trawlers were also used to transport key personnel in limited numbers.

When a trawler crew learned via radio contact with rear services groups ashore that it would be unsafe to attempt a landing, they often dropped the cargo overboard in fishnets. The cargo, in watertight containers, was marked with buoys. When the area was safe, sampans and junks retrieved it. A trawler could not be legally intercepted in international waters. Junks and sampans that picked up the contraband were very difficult to identify among the 64,000 similar SVN fishing boats off the coast. When the coastal radar system began to operate in 1971, it could be eluded by the trawler crews' transferring their cargo to junks and sampans just outside the range of the AN-TPS 62; that range averaged about 23 n.mi.

There is some question as to just when Group 125 was established and to what NVN command it was subordinated. Sources agree that there was an organization in the late 1950s that was responsible for maritime infiltration into SVN and possibly for other communist resupply missions. The same sources indicate that Group 125 was probably formed about 1960, and certainly by 1962.


(C) Originally under NVN's naval command, Group 125 subsequently was probably responsible to the NVN high command. Because of the high-level control of Group 125, NAVFORFIVE intelligence section estimated in December 1970 that Group 125 had access to the most current information from all VC and NVA intelligence organizations.

(C) Group 125 trawlers originally operated out of Haiphong, but in mid 1966 as U. S. bombing of the Haiphong area intensified, they probably moved to Hainan. Two years later, with the bombing halted, the trawlers began to reappear in Haiphong. In 1972, an NVN prisoner revealed that infiltration trawlers regularly used the port of Hsin Hsing on Hainan. Use of this port would have eased trawler infiltration attempts while Haiphong was quarantined.

(C) Members of Group 125 wee fanatic communist who remained aloof from other naval personnel. The 125th maintained cover as a meteorological outfit. On infiltration missions, the ships were disguised as innocent trawlers from other Asian countries. Their hulls were generally painted a drab color for camouflaging when beached in SVN. Interrogation reports revealed that the crews of some of the trawlers had orders to raise mainland China's flag when they were in danger of being fired upon.

(U) Security was extremely tight. The crew members' knowledge was severely restricted to a need-to-know basis, as was information available to the cadre who made the trip. Each trawler had a self-destruct system to preserve the secrecy of the organization and its mission and to prevent supplies and personnel from falling into enemy hands. The self-destruct system also indicted that the loss of these trawlers was not too important to NVN because of increased Chinese maritime support.

WBLC Infiltration

(C) Another enemy transportation group was in charge of infiltration by WBLCs across the 17th parallel. It was learned in 1965 that the VC would take South Vietnamese craft and crews to NVN, load supplies, and return to SVN.

(C) There is little documentation of the organizational structure behind the activities of the communist WBLCs that crossed the 17th parallel with supplies and personnel. According to the CINCPAC Infiltration Study of 24 July 1967, a transportation group was established in NVN during mid 1966 to organize the flow of supplies into SVN by WBLCs. There was no indication this group was associated with Group 125. WBLCs infiltrating to SVN probably originated from the coastal area between Ben Thuy (between the 18th and 19th parallels) and the 17th parallel. Another organization, the Vinh Linh Sea Transport Unit, was also responsible for supply movement to northern MR-1. This unit sent supplies from Vinh Linh (just north of the DMZ) to SVN by sampans and small junks within the surfline.


Coastal Transshipment

(U) In addition to these different infiltration methods, Market Time had to cope with intra-SVN enemy transshipment by junks and sampans. Transshipment was aided by the fact that much of the 1,000-st. mi. SVN coast was not under SVN control. Coastal transshipment seems to have been a purely local phenomenon. Some of the areas in which transshipment occurred were traditional routes that were consistently reported over the years. The route from the Three Sisters area across the Vinh Rach Gia in MR-4 was such a route. Transshipment also took place when inland routes were made hazardous or inconvenient by geography, weather, or allied operations. Transshipment along the coast of MR-1 and--2 was the safest and easiest method of redistribution of supplies in these areas. After Sea Lords began to interdict communist resupply routes in MR-4, there were increased reports of transshipment along the coast.

(U) Market Time forces rarely captured contraband from the thousands of junks they searched. Arms and ammunition could be easily jettisoned before a search. The VC could produce false papers, and the distinction between legitimate food shipments and enemy resupply efforts was generally impossible to make.

(U) Some infiltration occurred in the Gulf of Thailand from Cambodia by small boats, but like transshipment, this seemed to be under local control. Many of the coastal area accessible to transshippers were inaccessible to deeper draft coastal surveillance patrol craft.

(U) Beginning in 1970 reports of coastal transshipment in MR-4 were used by NAVFORFIVE to illustrate trends. Most of the reports were low level and unconfirmed, but NAVFORFIVE suggested that the overall number of such reports indicated that in 1972 an increase in coastal transshipment was occurring. The problem with this approach was that each report of transshipment activity did not deal with the same number of craft or people, so that more reports involving fewer junks and sampans might not mean an increase in activity. No adequate measure of effectiveness was developed to gauge Market Time's ability to intercept or otherwise hinder enemy coastal transshipment.

Other Seaborne Resupply

(C) In addition to direct seaborne infiltration into SVN, there were other forms of communist seaborne resupply with which Market Time did not deal. Form October 1966 to July 1969, the communists delivered between 11,000 and 19,400 metric tons of military supplies to Sihanoukville destined for the VC in MR-3 and 4. There is also a theory, proposed by the Naval Ocean Surveillance Information Center (NOSIC), that merchant ships smuggled arms up the Mekong River for the VC. This theory was never proven conclusively but evidence suggests it is plausible (Appendix H). There is also a possibility that the arms and munitions were smuggled into SVN by junks that lightered the supplies from merchant ships off the SVN coast.



For the first half of 1962, the U.S. Navy and the VNN participated in coastal surveillance exercises. The earliest patrols began in December 1961 with units from U.S. Minesweeping Division 73 and VNN patrol craft (PC)--174 foot submarine chasers--operating just south of the 17th parallel. Seventh Fleet aircraft also made periodic reconnaissance flights.

In February 1962, the patrols extended their limits from 30 n. mi. offshore to the Paracel Islands. By early March, the U.S. was authorized to patrol north of the 17th parallel as long as U.S. ships avoided the waters off NVN. This change was sparked by the discovery of North Vietnamese junks that would simply cross the 17th parallel when they were spotted south of that line. To train the SVN, the U.S. placed shipriders aboard the VNN PCs, and the Vietnamese placed liaison officers aboard U.S. ships. Since there was no authorization for U.S. ships to board and search suspicious contacts, radar was used to vector VNN units to the scene.

Also in February 1962, a patrol was established in the Gulf of Thailand between An Xuyen Province and Phu Quoc Island. The objectives were the same as the northern patrol: train and improve the Vietnamese, determine the extent to VC infiltration, and prevent infiltration. U.S. forces stayed clear of the Cambodian border; the Vietnamese units usually operated in the shallow waters of the Gulf of Thailand, not in company with U.S. destroyer escorts. The system of shipriders and liaison officers instituted in the northern patrol was incorporated into this exercise, as was the U.S. radar vectoring of VNN units to a contact.

The record of both patrols through March 1962 confirmed a lack of extensive seaborne infiltration of VC supplies into SVN. The U.S. Navy determined that enemy infiltration by sea was limited to high-priority shipments of vital material and key personnel.

SVN official must have feared VC seaborne infiltration. In December 1963, SVN established a blockading force around An Xuyen Province to counter communist infiltration there by way of Phu Quoc and other VC-controlled islands in the Gulf of Thailand. One section of the blockade covered the west coast of An Xuyen Province, another covered the east coast of An Xuyen, and another section covered Phu Quoc.

The patrol units consisted of one to three PCEs (185 foot patrol escort craft), four PGMs (102 foot patrol motor gunboats), an LSIL (159 foot light infantry landing ship), and an oiler and light cargo ship to replenish the patrol force. (Appendix A describes characteristics of the PCE and PGM.) Each ship operated with several junks. The Coastal Force junks patrolled inshore in groups of two or three, and the Sea Force ships patrolled out to 10 n. mi. offshore.


One of the anti-infiltration procedures adopted was biweekly air reconnaissance by SVN air force planes with U.S. and Vietnamese naval observers aboard. These flights covered the area from Phu Quoc to Con Son Island. Several Seventh Fleet P-2s (see Appendix C) monitored Sea Force and Coastal Force activity in the Gulf of Thailand. The need for establishing prohibited zones was recognized, and U.S. advisors recommended relocating fishing villages so that local fishermen would not be in restricted areas.

In 1964, the Sea Force patrolled the entire coast of SVN, with about half the force underway daily. The force consisted of 40 ships at the beginning of 1964 (and acquired four more before the end of the year). Initially, the Coastal Force was a paramilitary organization of motorized and sail-only junks. Under the Military Assistance Program, a new more seaworthy series of junks, Yabuta junks, was built. In October 1964, the U.S. Naval Advisory Group (NAG) was investigating a small, meal hulled patrol boat for VNN use and was considering the U.S. commercially available aluminum Swift boat; the Swift would later become an integral part of Market Time.

With these early coastal patrol efforts came the groundwork for the Market Time concept. The Vietnamese, with U.S. shipriders and with more patrol ships, were considered capable of doing an effective coastal surveillance job. The effectiveness of Vietnamese patrols was questionable in light of later evidence suggesting that at least 40 trawlers (60 to 100 ton capacity) had infiltrated before Market Time. The areas of emphasis for the earliest patrols were the 17th parallel and the Gulf of Thailand. These were traditional areas of high coastal transshipment activity, while the destination of the trawlers appears to have been the mouths of the Mekong.

Before Market Time, U.S. Navy advisors had reported that efforts of the SVN Coastal Force and Sea Force patrols were rather half hearted with a great reluctance to patrol at night. According to MACV, two incidents in early 1965 provided the immediate impetus for Market Time.

From 11 to 24 January 1965, U.S. Navy P-2s flew 14 random flights over Vietnamese patrol areas along the entire SVN coast and observed many VNN craft at anchor instead of patrolling. Emphasis was on night surveillance, and effective communication between U.S. aircraft and VNN patrol units and shore bases was proven to be feasible. After the VNN deputy chief of naval operations made one of these flights, patrol units showed a marked improvement.

On 16 February 1965, a helicopter on a medical rescue mission discovered a camouflaged ship in Vung Ro Bay. This ship, with a cargo capacity of 100 tons, was sunk by air strikes. Diving operations proved it to be a North Vietnamese infiltrator. Large arms caches found in the area indicated that other such trawlers had successfully infiltrated.


(U) MACV originally seems to have downplayed the VC/NVA capability for waterborne infiltration but later accepted a "significant" portion of VC infiltration as taking place by sea. The NAG, although subordinate to MACV, did not take the infiltration threat from the sea as seriously. The NAG March 1965 Monthly Historical Summary implied that while there were frequent reports of sea infiltration, almost none of those indicating large-scale activity was believable. The Vung Ro Bay discoveries, that publication stated, proved only that large-scale infiltration existed. At the same time, the Summary suggested sea infiltration as a strong possibility because of the appearance of arms and ammunition similar to those discovered at Vung Ro Bay in other parts of SVN. There was a possibility, however, that these munitions were delivered through Cambodia and not directly infiltrated by sea.

(U) The most significant infiltration information available at the time Market Time was established is contained in the "Buckley Report," published in February 1964. That study reached conclusions similar to the March 1965 NAG Summary--that there was no hard intelligence proving large-scale infiltration of supplies or men by sea. Although there were many reports of such activity, reliability of these reports was questionable. According to the Buckley Report, information concerning the infiltration of special personnel and articles needed by the VC did not indicate that such infiltration ever occurred south of Saigon.

(U) Two early Market Time commanders apparently believed at first that the threat of sea infiltration was not particularly significant. One suggested that there was no real evidence of infiltration that MACV wanted the U.S. Navy to prevent. As late as June 1965, the other commander would not accept sea infiltration as a fact anywhere but at Vung Ro Bay.

(U) In Summer 1965, General William C. Westmoreland (COMUSMACV) reiterated his belief that 70 percent of VC infiltration took place by sea. CTG 115. 4, in the Gulf of Thailand, commented that he had seen no evidence to support this contention. COMUSMACV and the Market Time commanders continued to disagree for a few years about how much seaborne infiltration was taking place.

(U) While adequate information on the scope of enemy infiltration seems to have been lacking at the inception of Market Time, evidence accumulated later confirms the existence of extensive seaborne infiltration before Market Time and seriously questions the Buckley Report's assertion of no infiltration south of Saigon. Documents captured in April 1965 reveal that between January 1964 and January 1965, two trawlers a month infiltrated MR-4 and a VC medical cadre captured in June 1965 revealed that from 1960 through October 1964, 20 trawlers infiltrated, destined for the mouths of the Mekong.

(C) The Central Intelligence Agency (CIA) indicates that while the magnitude of the enemy infiltration effort into the rest of SVN before Market Time is difficult to assess, such an effort did indeed exist. The CINCPAC/CINCPACFLT Infiltration Study of July 1967 listed these


reports of possible trawler infiltration before Market Time; 20 in 1963, 15 in 1964, and six to seven in 1965.

(C) Similarly, the Defense Intelligence Agency (DIA) believes that before 1965 at least 40 trawler infiltration attempts were made, peaking in late 1964 and early 1965. If there were, in fact, at least 40 trawler infiltration attempts before Market Time, COMUSMACV's assertion that much of the VC/NVA resupply was by sea seems plausible.

(C) While VC captured in June 1965 suggested that at least some of the trawlers were 60 ton capacity ships, DIA believes that the trawlers used for infiltration during the early period were capable of carrying 100 tons of cargo. The DIA estimate corresponds with later inventories of NVN trawlers used for infiltration (Appendix F). The June 1965 interrogation is in accord with DIA's belief that the Mekong Delta--and more specifically Kien Hoa Province-- was probably the destination of early infiltrators. DIA also suggested An Xuyen as a probable destination. The early Market Time concept of steel hulled trawler infiltration was thus based on inadequate intelligence.




Planning the Operation

ComUSMACV held a meeting in Saigon from 3 to 10 March 1965 to plan a combined U.S. Navy/VNN coastal surveillance patrol operation. On 15 March, President Johnson authorized Seventh Fleet patrols off the SVN coast. The operation was given its unclassified name, Market Time, on 24 March.

Establishment of the operation was based on these assumptions:

  • Seaborne infiltration of SVN had been taking place and would continue unless preventive measures were taken.

  • Such activity took the form of coastal infiltration by steel-hulled trawlers and wood-hulled junks.

  • There were only limited U.S. Navy shallow-draft patrol craft available.

  • The U.S. was not yet authorized to board and search, and such authorization was required.

Because of the limited number of U.S. Navy shallow-draft boats, the original plan for detecting and preventing coastal infiltration directed the U.S. Navy to help the South Vietnamese increase the quantity and quality of their searches of small craft. Since the U.S. Navy initially had no boarding authority, U.S. ships detected, tracked and reported suspicious contacts to VNN units, then would vector them to the contacts. A VNN liaison officer was to be assigned to each U.S. unit, and the NAG, in turn, assigned U.S. officers as advisors for junk division, Sea Force patrol ships, and the coastal surveillance centers.

Market Time originally came under the operational control of ComSeventhFlt because the U.S. first planned to commit only large patrol ships to the surveillance operation. VADM P. P. Blackburn, ComSeventhFlt, became the first Market Time commander, Commander Task Force (CTF) 71. The NAG, subordinate to MACV, served as the link between the Seventh Fleet and the VNN.

Assignment of Forces

At the beginning of the operation, the coast of SVN was divided into 8 patrol areas, with at least one ship assigned to each area. Five coastal surveillance centers (CSCs) were established--at Danang, Qui Nhon, Nha Trang, Vung Tau, and An Thoi--to


coordinate the VNN and U.S. Navy units. (Figure 2). A barrier 40 n. mi. long and 10 n. mi. wide was established at the 17th parallel, with at least 3 U.S. ships on station, a P-3 continuously on station, and an EC-121 flying at night to within 50 n. mi. of the Chinese island of Hainan.

For the first 3 months of Market Time, TF 71 averaged 15 ships (destroyers and minesweepers) on station. In June and July, the destroyers were replaced by 14 DERs, most of them about to be decommissioned; appendix B describes the patrol craft used in Market Time. The DERs were more efficient ships for countersea infiltration work because they burned less fuel, had superior endurance, and had better electronic capabilities.

The concept of the U.S. Navy's role in Market Time was changed in April at a meeting of SecDef, SecNav, and CinCPac with a decision to purchase 20 Swift boats from Seward Seacraft. (Appendix B). One Swift boat (PCF) was estimated to replace 5 Vietnamese Coastal Force motorized junks. The Swift boat could handle up to 36 hours on patrol, although 24 hours was preferable. The Swift radar would vector Vietnamese junks to suspicious contacts in the inshore areas and would lead Coastal Force units otherwise unable to operate at night, to junk concentrations. A MACV study in April 1965 suggested that Market Time obtain 54 Swift boats by 1 January 1966.

One of the more important factors that brought about the decision to expand the U.S. Navy's role in Market Time must have been the observation that the Coastal Force and the Sea Force were half-hearted in their patrols. Another factor involved the VNN PGMs; their crews were originally supposed to have given moral support to junk crews, and they were supposed to have aided and encouraged the junks on night patrols. But the PGM did not prove to have the necessary shallow-water capability.

While expansion of the U.S. Navy's role in Market Time was being conceived at the April conference, another type of shallow-draft patrol craft was discussed. The 82-foot Coast Guard Cutter (WPB) seemed to be the best available boat for coastal surveillance operations. The Coast Guard agreed to loan 17 WPBs to the Market Time force; these units began arriving in June.

Since the nature of the U.S. Navy's role in Market Time had expanded to include shallow-water surveillance, the operational control of the Coastal Surveillance Force was transferred in April to the NAG, subordinate to MACV. The NAG would have to expand its resources, since its role would encompass an operational as well as an advisory command.

As the operation was building up its force levels, photoreconnaissance aircraft finished a survey of the entire SVN coast during April. P-2 aircraft based at Tan Son Nhut and P-3s (see Appendix C) based at Sangley Field in the Philippines patrolled the coast from Vung Tau to the DMZ. In May, a P-5 seadrome was established to help the P-2s at




Tan Son Nhut with the southern coastal patrol. Through July, the aircraft tracks were varied to randomize the patrols and to experiment with different tracks, and 2 aircraft were to be on station at all times.

Barriers 1 and 2 were flown during the greater part of the period between 30 May and 30 July (see Figure 3, with Barrier 1 flown by P-2s from Tan Son Nhut or P-5s from Con Son Seadrome and Barrier 2 flown by P-3s from the Philippines. The aircraft were to report steel-hull contacts to the area commanders. These barriers were aimed at locating all contacts within 45 n. mi. of either side of the track.

Barriers 3, 4, and 5, flown by P-2s, P-3s, and P-5s, respectively, offered a greater probability of detection with continuous coverage than did Barriers 1 and 2 (90 vs. 70 percent). (Figure 4). Because of the small number of P-2s at Tan Son Nhut, however, Barrier 3 could not be continuously covered.

Barriers 6 and 7 were devised to bring the tracks inwards towards the SVN coast. (Figure 5). This concept was coordinated with the surface forces being stationed within 12 n. mi. of the coast. The air patrols were directed to concentrate on all targets within 40 n. mi of the coast, since surveillance beyond that range was not practical in relation to the effort expended.

Market Time air patrols were most commonly flown on the Blue and Red tracks (Figure 6). Aircraft on these tracks maintained surveillance on coastal areas in addition to randomly searching for steel-hulled contacts up to a distance of 40 n. mi. from the coast. One leg of the patrols was flown inshore, and the other was flown 40 n. mi. out to sea.

Through the entire operation and on whatever track they were flown, the VP patrols observed and determined normal coastal and off-shore junk or ship traffic patterns. They reported to the CSCs all deviations that could suggest infiltration routes or operations in progress. The aircraft investigated and reported all ships that could not be identified and were within 40 n. mi. of the coast of SVN or on a course toward the coast. To exchange information, VP aircraft established voice contact with VNN coastal groups and Sea Force Ships and with U.S. Navy task groups, task units, and patrol ships when they were nearby. The aircraft were prepared to be vectored to investigate contacts when requested to do so by surface forces.

During daylight, contacts were "rigged" (photographed) and their positions, descriptions, courses, and speeds passed to the CSC. At night, vessels were identified by their running lights or by coded light interrogation response between the aircraft and the contact ship. Suspicious contacts warranting further identification were illuminated by air-dropped flares.










In May 1965, new rules of engagement (ROEs) authorized Market Time units to board and search vessels not clearly engaged in innocent passage within the 3-n. mi. territorial limits of SVN and within a contiguous zone extending 12-n.mi. offshore. Beyond the 12-n.mi. limit, the U.S. Navy was authorized to search any vessel believed to be South Vietnamese. (See Appendix I).

Different surface patrol concepts were tried during May. Instead of patrolling randomly, 12 of the 15 Market Time ships patrolled the 4 northern areas in predetermined courses parallel to the coast so there would be continuous radar coverage of the northern SVN coast. Random patrolling was continued by the remaining 3 ships in the 4 southern areas, which were supposedly less conducive to seaborne infiltration (Figure 7).

Whether the southern areas were, in fact, less conducive to sea infiltration is debatable. But at the time, discoveries of junk traffic across the 17th parallel and the Vung Ro Bay incident gave credence to the idea.

In mid-July, another surface patrol concept was tried as an experiment. Market Time ships began to patrol only within 12 n. mi. of the coast, deemphasizing possible contacts beyond the contiguous zone. This concept was intended to have the psychological effect of visible proof to both the enemy and the South Vietnamese that the U.S. Navy was supporting the VNN.

In July, before the turnover to NAG, SecDef ordered 34 more PCFs to equal the number proposed in the April MACV Market Time study. The Coastal Force was formally integrated into the VNN, an important psychological step for Coastal Force crews. By mid-July TF 71 destroyers had been replaced by DERs. Before Market Time was turned over to NAG, 17 WPBs had arrived. Nine were sent to An Thoi to form CG Division 11, and the remaining 8 were sent to Danang to form CG Division 12.

With expansion of the U.S. Navy's role in Market Time to include shallow-water patrols, support plans for the WPBs and Swifts had to be developed. Until YR-71 (a floating workshop) arrived at Danang and ARL-38 (a 328-foot former LST repair ship) arrived to anchor off An Thoi in mid-September, 2 LSTs (landing ships) supported the WPBs.

During the first 5 months of the operation, the U.S. Navy had gathered information on the types of vessels likely to infiltrate and the areas most conducive to enemy infiltration. Market Time developed a detailed knowledge of local operating areas, including fishing patterns, tides, VC-controlled areas, population distribution, and shipping traffic.

Building Up an Intelligence Capability

During Summer 1965, there was still no evidence suggesting the extent of enemy seaborn resupply. ComPatForSeventhFlt's final Market Time report at the end of July




noted that Market Time's effectiveness was hampered by very inadequate intelligence. CTF 71 received intelligence summaries from MACV, but reliability of these summaries was questioned. Except for the discoveries at Vung Ro Bay and a few other isolated incidents, there was very little hard intelligence. The available information was totally inadequate to assist in determining the position of Market Time forces.

Chief, Naval Advisory Group (CHNAG) started to build a Market Time intelligence network before he actually took control of the operation. The intelligence community usually dealt only with land and air warfare. It had to be reoriented to an awareness of the sea infiltration problem.

A Navy captain joined the intelligence section of MACV's staff. An agent network funded by MACV was set up by the VNN. U.S. Navy intelligence officers in Vietnam increased from 6 at the beginning of Market Time to 32 by July, with at least one intelligence officer at each CSC and 5 at NAG headquarters. By January 1967, of the 38 NILO officers, 23 were concentrated in the Delta in support of Market Time and Game Warden (the riverine operation).

TF 115 Established

On 31 July 1965, TF 115 under NAFG was activated when TF 71 was deactivated by ComSeventhFlt. CinCPacFlt, through ComSeventhFlt, retained the logistic support responsibility for TF 115.

RADM Ward, CTF 115 and CHNAG, added another patrol area off the coast of MR-4, which made a total of 9 patrol areas, each 30 to 40 n. mi. deep and 8 to 120 n. mi. long, with one DER in each area (Figure 8) or an MSO or MSC if not enough DERs were available. U.S. Navy Market Time operations were controlled from CTF 115 surveillance operations center in NAG headquarters, Saigon, while the VNN patrol operations were coordinated with U.S. Navy operations from the CSCs.

Setting Up Barriers and Increasing Force Levels

After the transfer of operational control of Market Time from ComSeventhFlt to CHNAG in July, there were no further major changes until the September conference in Saigon. There, the conferees discussed, among other topics, ComUSMACV's recommendation that additional patrol ships be made available to Market Time to increase the number of offshore patrol stations continuously manned from 9 to 25. The conference was attended by representatives from CinCPac, CinCPacFlt, OPNAV, and NAG. A study was conducted, refining the concept of operations for Market Time and recommending adjusted force levels based on the best available information of the nature of the threat.




That study (Landis Study) estimated that the VC needed to infiltrate 14 tons per day to maintain their level of operations.1 If the 14 tons were supplied by sea, they could have been moved by one 100-ton-capacity vessel every 7 days, by 28 junks of ½-ton capacity each day, or by combinations of the two. It was decided that the aspect of the threat most difficult to interdict--infiltration and transshipment by junks--should be the basis for developing a concept of operations. It was further determined that a 20-percent attrition would be unacceptable to the enemy. With increased force levels to achieve this attrition, it was assumed that Market Time would have a substantial capability against steel-hulled trawlers.

The study group suggested establishing 3 barriers--an air barrier and outer and inner surface barriers. The air barrier was to be flown with 2 tracks manned continuously. The Red Track was usually flown by P-2s from Tan Son Nhut or P-5 seaplanes, and the Blue Track by P-3s from Sangley Field in the Philippines (Figure 6). Both tracks consisted of one leg over the coast and the other 40 n.mi. offshore. In addition, small single-engine aircraft (L-19s) made two daily flights over the coastline; aircraft with sidelooking airborne radar flew intelligence and night missions; and a Vietnamese C-47 flew two to three surveillance flights a week over area 9 near the Cambodian border.

The remaining 2 barriers were to be patrolled by surface craft. The outer surface barrier, 10-15 n.mi. offshore, was manned by DERs, MSOs, and MSCs. The Landis Study suggested a formula that required the equivalent of 11, 17-knot ships on station. The inner barrier was to be patrolled by Swifts, WPBs, and VNN junks. Thirty more Swifts (for a total of 84) and 9 more WPBs (for a total of 26) were ordered. The first Swifts were scheduled to begin arriving in November. The Landis Study assumed maximum utilization of the VNN forces, implying that about 100 VNN units would operate inshore close to their coastal group bases, and 16 VNN patrol craft would be on station in the inner barrier.

Cam Rahn Bay, Vung Tau, Qui Nhon, and Cat Lo were planned as PCF support bases in addition to Danang and An Thoi after additional PCFs were ordered. By October, it was clear that ARL 38, which had arrived in September, could accommodate only 2 PCF crews.

A recommendation was made to house other crews in tents ashore. At the end of 1965, with 8 PCFs stationed at An Thoi, the crews lived in tents on Phu Quoc Island. (Since the island was largely controlled by the VC, 2 Regional Force companies were stationed there to protect the Market Time forces.)


1. Various estimates of enemy war material needs are presented throughout this research contribution. These estimates cannot be correlated with each other, and the sources do not adequately explain how the estimates were determined. They are given here to indicate official beliefs at given times throughout the operation.


Search Tactics

A concept for the investigation and search of junk concentrations was developed in October in Operation Roundup. Aircraft were to observe junk groups to determine their location and number. Patrol units would then surround the junks at night so that, in the morning, the junks could be forced into preplanned inspection areas. This exercise was tested in November off the mouth of the Cau Co Chien River, but without air surveillance. The initial exercise failed. A week later, with aircraft surveillance, junk concentrations were found and the concept was again tested. This time it worked.

By Spring 1966, U.S. Navy ships were boarding and searching about 15 percent of the junks they detected; the VNN searched additional junks along the coast. The 200 or so small craft of the Sea Force and Coastal Force had little or no ability to patrol at night. Night searches were handled by U.S. Navy shallow-draft PCFs and WPBs. The Coastal Force operated close inshore trying to prevent VC transshipment, while Sea Force ships patrolled further out to sea. Patrol areas were chosen by size, location of SVN coastal zone boundaries, areas of responsibility of VNN coastal groups, and coastal districts.

Two types of investigations were conducted by Market Time forces among the wood-hulled ships and boats: inspections and boardings. In an inspection, the patrol ship closely approached the junk, viewed its exposed cargo and observed the actions of the crew, or the Vietnamese liaison officer (when there was one) questioned the crew. In a boarding, the patrol ship sent a detachment aboard to check paper, inspect the cargo, and question the crew.

Different search tactics were used, including random searching and searching the nearest uninvestigated junk. In the former tactic, a junk in the searcher's assigned area was randomly selected for boarding. In the latter, the object was to search the largest possible number of junks in the surveillance zone. The disadvantage of the nearest-uninvestigated-junk tactic was that the infiltrator could evade by ensuring there was always another boat between it and the searcher. When detained by U.S. Navy or Coast Guard crews, suspects or cargo were turned over to the Vietnamese.

There was a trend toward an increased surveillance effort shown in the numbers of junks and people searched as the end of October 1965 approached, but the effort seems to have decreased in November. This decline may have been a combination of low Vietnamese morale and the northeast monsoon, which reduced both the numbers of patrolling craft and fishing craft. In addition, U.S. Market Time forces had problems with the VNN because of units that would report themselves "on patrol" as long as they wee out of Saigon. After a meeting between CHNAG and VNN's Chief of Naval Operations about VNN investigation procedures, the VNN units were made to take the terms "on patrol" and "investigation" more literally.


In November, for the first time, and again in December, heavy weather curtailed some Market Time activities.

The WPBs on the 17th parallel had to be called into Danang because of high seas. As Market Time participants learned, operations on the east coast of SVN were hampered during the northeast monsoon (November and December). And during the southwest monsoon (June and July), the Gulf of Thailand was excessively rough.

Arrival of PCFs

PCFs began to arrive in SVN at the end of October; by the end of 1965, 8 Swifts were stationed at An Thoi to form Boat Division 101. In January 1966, 6 more PCFs arrived to form Boat Division 102 at Danang based at first on YR-71 and then on YFNB-21 (barracks and workshop craft) until the arrival of an APL (barracks craft). In February, Boat Division 103 was activated at Cat Lo, and the Swifts patrolled the RSSZ in conjunction with 9 WPBs that also arrived at Cat Lo in February to form CG Division 13. The PCF divisions had 1½ crews/boat; the more seaworthy WPBs had one crew per boat.

In January and February, the Swifts started a series of exercises to determine their most effective use in Market Time. These exercises included gathering hydrographic information and examining DER support of the PCFs. PCFs were found to work effectively only in seas of 6 feet or less. Underway refueling from a DER was feasible, increasing a Swift's time on station from one to 120 days.

Similar exercises were held to determine how well WPBs could function away from their shore bases. It was demonstrated that 3 WPBs could function at a distance of more than 100 n. mi. from their bases when supported by a DER. The effectiveness of vectoring WPBs to targets detected by the DERs was also demonstrated. The combined effort of PCF/WPB/DER units resulted in more aggressive patrols and increased morale.

In the future, the use of DERs as mother ships for the PCFs would depend on the distance the PCF had to patrol from its base and on the nature of the junk traffic to be searched. In areas where junk traffic did not transit from the outer barrier to the inner barrier such as off Cam Ranh Bay, close coordination between DER and inner-barrier patrol craft was unnecessary. U.S. Navy efforts were not well coordinated with the efforts of the VNN junks (until Vietnamization began), although direct liaison between all the U.S. Navy and VNN forces was encouraged for information exchange.

Using the experience gained in the January/February exercises, Market Time forces participated in four special operations during March. Operation Jack Stay was combined U.S. and Vietnamese Marine thrust into the VC-controlled RSSZ. Some Market Time units (9 WPBs and 6 PCFs) were used to patrol the major rivers of the RSSZ in an operation designed to prevent both infiltration and exfiltration of the VC in the RSSZ to protect the main shipping lanes to Saigon. The three other special operations were more similar to a blockading operation that took place in February. (That operation was based on intelligence reports of enemy movements in an area ashore; it supported land operations.)


(U) The four operations reiterated the concept of the DER as mother ship for PCFs and WPBs in situations when it was necessary for the smaller craft to be too far from their shore bases to make their normal patrols. The DER/WPB/PCF team proved to be more efficient than the MSC or the MSO/WPB/PCF team. The minesweepers lacked space to berth the extra PCF crews and radio equipment with which to communicate with coastal groups and within a minesweeper's own task group. The exercises demonstrated that rapid deployment and concentration of forces were feasible to meet a threat anticipated by intelligence reports.

(U) Under NAG, the Market Time force composition and barrier configurations were established. The inner barrier was manned by the VNN Sea Force and Coastal Force. U.S. Coast Guard WPBs and U.S. Navy PCFs were added. Larger U.S. Navy ships (DERs, MSOs, and MSCs) patrolled offshore in the 9 patrol areas. U.S. Navy VP aircraft flew mainly two patterns (the Red and Blue tracks). Under the NAG, operational tactics were experimented with, and DER/PCF/WPB teams worked to coordinate their patrolling activities. There was little coordination between the VNN Sea and Junk Force and the Swifts.

Enemy Activity

(U) As Market Time progressed, more information on enemy activity came to light, suggesting that the VC had used and would continue to use seaborne infiltration to transport supplies into SVN. At the end of April 1965, a large arms cache was discovered in Kien Hoa as a result of 3 months of intelligence work (started before the operation was officially established). This cache was found to be at a more permanent site than that at Vung Ro Bay, and it included 6 Chinese portable flamethrowers. This was the first known instance of flamethrowers entering SVN. Intelligence officials determined that the weapons were to have been distributed north and west of Saigon and surmised that they had probably been delivered by sea.

(U) At this time, a key VC official was captured. Documents were found pinpointing the district of Thanh Phu in Kien Hoa Province (MR-4) as a major sea infiltration area. The documents indicated a large ship anchored 3 to 5 n. mi. offshore twice a month to be offloaded by 3 motorized sampans.

(U) A VC who was knowledgeable about sea infiltration stated that from January 1964 to November 1965, an average of 2 steel-hulled ships per month infiltrated arms and ammunition into An Xuyen.

(C) The first trawler detection since February took place on 31 December off An Xuyen Province. The trawler aborted its mission and returned to Chinese waters. Photography proved that this trawler was similar to the one discovered at Vung Ro Bay. Since this trawler had a Chinese nationalist flat painted on it, the U.S. commander on Taiwan began to send NAG the name, registry number, estimated date od departure and estimated date


and location of arrival of all Chinese Nationalist trawlers to ensure detection of further infiltration attempts under the guise of that neutral flag.


On 1 April 1966, U.S. Naval Forces, Vietnam (NavForV) was established as the Naval component commander for ComUSMACV.

Later that year, two things happened outside of Market Time that ultimately affected seaborne infiltration--the Sea Dragon Operation and the opening of Sihanoukville to communist bloc nations.

Sea Dragon, consisting of U.S. and Australian ships and support aircraft dedicated to interdicting NVN's coastal logistics traffic between the 17th and 20th parallels, went into effect in November. By the end of 1966, this operation had destroyed 382 WBLCs and damaged 325, many of them headed for SVN. During the 2 years of Sea Dragon, the numbers of WBLCs crossing the 17th parallel dropped sharply, except during standdown periods.

In December 1966, Sihanoukville was opened to communist bloc nations, providing logistic military support the VC/NVA in MR-4 and-4 and in southern MR-2. Any great pressure for sea infiltration into the Delta would have been certainly eased and possibly eliminated by the impunity with which the VC could now transport supplies through Cambodia to the Delta by the extensive inland waterway network and land routes in MR-4.

In May 1966, soon after NavForV was established, TF 115 detected a trawler heading for MR-4. The trawler was destroyed by Market Time forces but much of its cargo was retrieved. The most significant item recovered was 120mm. mortar ammunition manufactured in China in 1965; it was the first time this type of ordnance had been discovered in SVN. In addition, the discovery of 12. 7mm. APO ammunition manufactured in China in 1965 also indicated a shortage of ammunition for communist troops in SVN.

Another infiltrating trawler heading for MR-4 was captured in June. Some of the ammunition boxes that were salvaged were dated 1966, implying the communists had a rapid distribution system.

The disagreement between NavForV and MACV on the extend of seaborne infiltration came up again in August 1966. ComUSMACV was told about infiltration from the sea in MR-2 and-3, proven by cart tracks and arms caches on the beaches. CTR 115 did not agree with this theory.


As more PCFs arrived, incident with junks increased, probably an indication that much of the infiltration/transshipment was not being detected. The more Market Time forces there were available, the more activity they discovered. By the end of 1966, 96 WBLCs had been destroyed, and large quantities of medical supplies, ammunition, and equipment seized.

Another trawler infiltration attempt was detected in December. But the trawler, probably headed for Binh Dinh province, aborted its mission. In January 1967, however a trawler was detected offloading onto Sampans near the mouth of the Bo De River in MR-4. After an exchange of gunfire with Market Time forces, the trawler exploded possibly as a result of a self-destruct system. The hull was never found and, therefore, no contraband located. Salvage operations were hindered because the exact location of the trawler had not been plotted, and the general area was controlled by the enemy.

In March 1967, another steel-hulled trawler attempting infiltration into Quang Ngai was detected by Market Time forces. It was destroyed by its own crew, but some cargo was recovered.

Most reports of enemy waterborne activity in this area (off the coasts of MR-1 and-2) were hearsay from low-level sources. In March, a high-level information source became available on seaborne deliveries into enemy MR-5.2 That source was a 39-year-old North Vietnamese major who defected ("rallied") to the South Vietnamese on 25 March 1967 in Quang Ngai province. His credentials stated that he was the training officer in enemy MR-5; he said that more than half the supplies to MR-5 came by sea during 1965 and 1966. (MR-5, by his definition, included the coastal provinces between the southern borders of Thua Thien and Khanh Hoa provinces.)

He estimated that, so far in 1967, only 20 to 30 percent of MR-5 supplies had arrived by sea. Although his statement corroborated earlier low-level reports, they failed to clarify the type of supplies included in the sea-borne infiltration.

In April, as corroboration for the defector's report, there were increasing low-level reports indicating that seaborne infiltration and coastal resupply were being used to meet the logistical requirements of VC/NVA forces in northern Binh Dinh and southern Quang Ngai Provinces. By April, however, the number of low-level reports infiltration by sea in SVN from Cambodia had decreased.


2. The VC and North Vietnamese had their own system of subdividing SVN into military regions.


The commander of CG Division 11 in the Gulf of Thailand felt, early in March, that the VC had been driven to inland canals and that intracoastal traffic had been eliminated. There is no way to corroborate this; but it is plausible in light of the VC's freedom to use Cambodia without harassment. Despite Sea Dragon, there were still frequent reports in April 1967 of the infiltration of troops and supplies from NVN by WBLCs just below the DMZ.

In July, ComNavForV said there had been a marked decrease in seaborne infiltration because of the effectiveness of Market Time and increased control of the coast by friendly military assistance forces. Market Time forces had been concentrated in areas shown by intelligence to be infiltration points. In July, perhaps because of the extra vigilance of Market Time forces off MR-1, TF 115 forces detected a steel-hulled trawler attempting infiltration into Quang Ngai province. The trawler was run aground and the cargo salvaged.

By July 1967, the enemy was probably moving less than 5 percent of out-of-country requirements of Class II, IV, and V3 materials by sea, and that most of the seaborne infiltration to MR-1 was by WBLCs.

Multitrawler Infiltration attempt Following Tet

With the fighting during Tet in February 1968, there was a decrease in routine activity for Market Time forces. The fighting prevented indigenous junk and sampan traffic from using many inland waterways as access to the ocean, and bad weather inhibited normal activity of the watercraft.

During late February, 5 trawlers were detected attempting to infiltrate. One trawler aborted its mission before reaching SVN's contiguous waters. Several days later, on 28 and 29 February, 4 trawlers came under Market Time surveillance as they approached the SVN coast in MR-1,-2, and-4. This was the first detected coordinated multiple infiltration attempt. It was obviously a crisis-oriented effort after the heaviest fighting of Tet, as evidenced by the large quantity of emergency medical supplies--particularly blood plasma--carried by one of the trawlers. Three of the trawlers were destroyed and the fourth aborted its mission.

After this attempted multitrawler infiltration, no other infiltrating trawlers were detected until August 1969.


3. Class I - food and water.
Class II - weapons, vehicles, signal equipment, and clothing.
Class III - POL.
Class IV - construction material.
Class V - ammunition, etc.


Before 1965, trawler infiltration focused on the Delta. In 1965, there was an NVN main force buildup in MR-1 and-2, so the trawler infiltration effort was expanded to include northern SVN. MR-3 potential beach sites failed to meet most security requirement, and the support organization needed to meet infiltrated supplies was never generated. Supplies were moved across rivers to MR-3 from the Mekong estuaries.

In the first trawler infiltration era, there were two main trawler corridors--the Quang Ngai-Binh Dinh corridor and the an Xuyen corridor (Figure 8). The upper section of the corridor roughly parallel the Hong Kong-Singapore/Shanghai-Singapore routes, probably to serve as cover for the trawlers and to simplify navigation. During that time, the trawlers did not seem inclined to abort their missions. The attempts were probably designed to meet specific short-term supply needs, as illustrated by the 4 simultaneous attempts following the Tet offensive. In addition, 3 trawlers tried to take advantage of Christmas' and New Year's stand-downs.

Market Time Status at NavForV Takeover

After NavForV was established, CTF 115 spent the rest of 1966 building up to the force levels suggested by the Landis Study. But a review of the Landis Study in July 1966 showed that some of the assumptions on which it was based were no longer valid.

The intelligence estimates of VC resupply requirements in SVN were revised. The VC/NVA were credited with the ability to infiltrate 269 tons a day by land and river lines of communication (LOCs) through Laos. But as additional forces were infiltrated, their resupply requirements would exceed land and river LOC capabilities by late 1966. The intelligence section of MACV expected a renewed emphasis on the seaborne route.

Not only was the estimate of the threat revised, but it was pointed out that all the positions recommended by the Landis Study had not yet been filled. While CTF 115 waited for the remainder of his requested forces, the primary emphasis of the surface effort was on random patrols within assigned zones rather than on establishing a perimeter barrier around a defended zone.

In addition, the Landis Study had assumed that 100 SVN coastal units and 16 SVN patrol craft would be available to patrol the coast. An average of 100 inshore units were on station, but only 10 patrol vessels were available; these were equipped with unreliable radar. Although the Landis Study had implied that an attrition rate of more than 20 percent attrition could be expected on steel-hulled trawlers penetrating the outer barrier, the need to increase this attrition rate (especially in high-threat areas) was determined in mid-1966.

The TF 115 OpOrder of April 1966 estimated that the total VC requirements for one day of operations could be met by 180 medium-sized junks. The OpOrder further noted that


there was no effective control of motorized junks licenses to operate in SVN waters. ComNavForV initiated a junk-boarding/manifest-reporting program to build up a knowledge of coastal and riverine traffic, and areas for housing detainees were set up.

Secondary Market Time Missions

Once the basic operating concepts were learned, Market Time forces began to participate in operations secondary to their main mission. In addition, until Game Warden was started in May, WPBs and PCFs participated in river patrols.

As a result of a January MACV directive to develop defenses of major harbors in SVN, Market Time activities expanded into harbor defense (operation Stable Door) in mid-April 1966. A harbor entrance control post, radar surveillance, and surface-craft patrols were to be established at each major port.

Market Time forces increased their support of ground operations during 1966 and 1967 to prevent enemy infiltration/exfiltration. From one of these support operations, Tee Shot V, came three emergency action plans for Market Time units to establish barriers or concentrated area inspections of junks and sampans. These plans were to be executed rapidly with minimum communications. Plan Line Plunge established a barrier perpendicular to the coast to intercept traffic parallel to the coast; plan End Around placed a barrier parallel to the coast to intercept traffic travelling perpendicular to the coast; and plan Corral established a specific area of search when closer-than-normal scrutiny of a junk concentration was required.

Naval Gunfire Support (NGFS)

By mid-1967, NGFS of ground forces bean to increase as a secondary Market Time mission. As freedom of movement was denied to the enemy inland, exfiltration operations became more important, resulting in more opportunities for NGFS. Originally, NGFS had been frowned upon as interfering with coastal surveillance.

Psychological Operations

Another mission of Market Time was well underway in 1966: the psychological operations (PsyOps) program. This program was calculated to counter VC propaganda, warn junk and sampan crews against evading an intensive U.S. Navy or VNN search of an area, and make contacts that might be a good source of intelligence. In the course of a day's search, kits of soap, dehydrated milk, sewing kits, cooking oil, toothpaste, cigarettes, and Kool Aid, among other items, were often distributed to junk and sampan crews to compensate for the burden of submitting to search.


But questions were raised about the value of such a giveaway program. Or, as the 1967 Coastal Division 13 Commander commented in his end of tour debrief: "The goodie bags get you little more than a highly indignant attitude on the part of the Vietnamese when you show up without them."

There was also some question as to how effective the leaflet programs would be if many members of the local population were illiterate. On the other hand, there seems to be no disagreement that first-aid treatment and towing of stranded local craft was a substantial way to accomplish PsyOps goals.

Another form of PsyOps more substantial than the giveaway program was the support by some U.S. Navy and Coast Guard units of SVN institutions such as orphanages. By August 1966, the Island Adoption Program was underway in the Gulf of Thailand. Under this program, each Gulf of Thailand Market Time unit was assigned a specific island, together with the responsibility of furnishing education and informative materials to counter VC propaganda, providing medical treatment, and improving the civilian-military relationship.

Coastal Surveillance Operations

By the end of 1966, Market Time forces had reached the programmed levels with the arrival of the last PCF in November, boosting the total to 84 Swifts and making up the 2 PCF losses suffered in 1966. From May to October, Market Time had tested 3 patrol air cushion vehicles (PACVs). They proved unsatisfactory in coastal surveillance operations. By spring 1966, the Red and Blue tracks were generally flown by Market Time aircraft with a 6-hour revisit time for each track. In March 1967, the flight tracks were flown about 60 n. mi. offshore and parallel to the coast instead of one flight leg over the coast. In 1966 and ruing the first quarter or 1967, whenever a seadrome was operating, P-5s flew from Cam Ranh Bay to aid the P-2s flying from Tan Son Nhut and the P-3s flying out of Sangley Field in the Philippines or U-Tapao, Thailand.

In April 1967, the P-5 Marlin seaplanes flew their last missions for Market Time. The decision was made to operate Market Time patrol aircraft out of Cam Ranh Bay and, by 1 August 1967, Cam Ranh Bay was fully operational. But aircraft were still patrolling for Market Time from U-Tapao, tan San Nhut, and Sangley.

Throughout Market Time, scheduling of patrols for the air barrier was hampered by the use of 4 different bases (3 of them out of country), not including the seadromes. Until mid-1967, the air barrier was manned by 3 different types of aircraft, each with its own varying capabilities and requirements. Two different types of aircraft flew Market Time patrols until 1969.


Disagreements developed in mid-1966 over how afar offshore the U.S. surface craft should patrol. In August, CTF 115 directed that normal patrols should be at least 1500 yards from the beach because of recent 57 mm. Recoilless rifles fired in the Gulf of Thailand. In MR-1, however, 80 percent of the junks to be searched were within that 1500 year limit, and complying with the directive would have resulted in totally ineffective patrols. A similar question arose over the rigid position of WPBs at a specific distance offshore. CTG 115. 4 believed the main barriers should be along the Cambodian border and the 17th parallel, and other barriers should be established in response to intelligence.

Other officers may have felt that too many restrictions were being imposed upon them from Cam Ranh Bay. However, the operation was showing signs of flexibility, as units were moved in reaction to intelligence. A concept of seasonally shifting the WPBs was developed, since the WPBs were more seaworthy than the PCFs. During the southwest monsoon, Swifts were stationed in the Gulf of Thailand and more PCFs moved north, where the weather and sea conditions were milder. The situation was reversed during the northeast monsoon. This shift, while allowing more flexibility in the operation and more efficient use of Swifts, lowered the morale of WPB crews.

In May 1967, 2 different types of ships arrived for coastal surveillance duty. The first 3 high-endurance Coast Guard Cutters (WHECs) arrived to replace DERs, and the new 165 patrol gunboats (PG0 arrived (Appendix B). The PGs were to patrol both the inner and outer barriers; they were chosen for their high speed, fire power, maneuverability, and shallow draft. Coastal Squadron Three was commissioned in August 1967 with 2 PGs. But problems developed almost immediately because of a lack of spare part and trained repair personnel. Furthermore, the PG did not prove to be as seaworthy as had been hoped, and provided only minimal living space for its crew.

Other maintenance problems arose. PCF hull corrosion was severe. Many hulls had been reduced to half their original thickness. In September 1967, a major overhaul program for the PCFs was devised to begin in December. During the next 6 months, 24 Swifts would be overhauled, 4 at a time, at Subic Bay, and Sasebo, Japan.

In June 1967, there was a buildup of forces in MR-1 because of the expected increase in enemy activity. In addition, "highboy" patrols by P-3s were added on moonless nights to the 24-hour-a-day low-level P-2 patrols usually flown below 2000 feet. These patrols concentrated on high-threat areas of the coast, flying tracks of about 120 n. mi. at 4000 to 5000 feet, 50 n. mi. off the coast. The patrols were to provide saturation radar coverage and continuity of plot for all contacts.


By August, tracks were being flown within the northern and central southern sectors of the coast. The aircraft flew parallel to and 70 n.mi. from the coast, and could deviate up to 50 n. mi., on either side to identify suspicious contacts (Figure 9).

The Coastal Division 12 detachment that had been at Chu Lai was activated as Coastal Division 16 in June. In July, a 4 boat detachment from Cam Ranh Bay's Coastal Division 14 began operations at the mouth of the Cua Viet River to bolster patrols just south of the 17th parallel and to free more Danang-based PCRs for patrol in support of Marines north of that city.

The boundaries of Game Warden were moved in September, 5 n. mi. inland in the river mouths south of Cape St. Jacques, and Market Time boats replaced the Game Warden LSTs and PBRs (28-foot river patrol boats). The area had become a VC free-crossing zone because Game Warden forces did not patrol the area effectively.

Air tracks were extended farther west over the Gulf of Thailand to provide surveillance of sea traffic bound for Cambodia. The northern minesweeper/destroyer escort barrier patrol was extended 40 n. mi. eastward along the 17th parallel. The Market Time air tracks were further revised in November. The tracks were expanded to three to achieve a maximum revisit time of 8 hours. Highboy flights were stopped, and the air barriers pulled from 70 to 55 n. mi. off the coast. The northern barrier section was flown by P-2s with one aircraft always on station. The central and southern sections were flown alternately by 2 P-2s and then one P-3 (Figure 11).

By the end of 1967, land-based radar sites were operating on the islands of Con Son and Poulo Obi. These sites had been chosen to cover the eastern coast and the tip of An Xuyen Province. Because of the great distance between the PCF/WPB bases at An Tho and Vung Tau, patrols in this area had tended to suffer.

By early 1968, although raids up rivers were not yet allowed for Market Time (they would become an integral part of Sea Lords later that year), there were some raids at Cua Song Bay Hap on the west coast of An Xuyen Province. To observe and thwart VC activity in the Gulf of Thailand, the Boston Whalers of the WPBs participated in small-boat operations to reconnoiter along the beach. They gave significant information on suspected infiltration routes. Coast watchers were placed on small islands off Phuy Quoc; while it discovered no contraband by early 1968, the coast watcher concept had potential.

Turnover of Market Time Assets to VNN

In mid-1966, VNN effectiveness was determined to be inadequate but improving. The quality of the commanders had a direct defect on the aggressiveness of Vietnamese patrols. A need was expressed for either good Vietnamese liaison personnel or language training


Figure 9: MARKET TIME BARRIERS--1967 AND 1968


for the U.S. Navy. The VNN response to challenge-and-reply procedures was generally poor, and restricted areas set up by the government were not being observed. The condition of Sea Force and Coastal Force ships and boasts was poor, and the Vietnamese had problems acquiring spare parts. Coordination between Market Time forces and the Vietnamese Coastal Force and Sea Force seems to have been almost nonexistent. Many of the liaison officers were ineffective and some were even prone to seasickness.

By 1967, however, the situation improved. Joint VNN-U.S. Navy procedures were attempted during April. Two 3-junk elements equipped with night observation devices patrolled the coast, and a WPB offshore vectored them to radar contacts with effective results. A VNN PCE took over the patrol duties of 2 U.S. Navy PCFs, freeing the Swifts for special patrols. In May, VNN PCEs relieved U.S. Navy MSOs in the first and second naval zones for 15 days each. And by September, a VNN PCE took over an area off the west coast of Phu Quoc. By 1 November, a milestone had been reached in Market Time as 4 VNN fleet command ships relieved U.S. units in the 4 coastal patrol zones.

Meanwhile, Commander, Coastal Squadron One was given the responsibility of establishing and operating a PCF training program for the VNN, geared to the eventual turnover of the entire inshore coastal operation. VNN Coastal Force effectiveness had declined as U.S. Navy-manned PCFs had increased in number. The scheduled turnover of Swifts was instituted to encourage Vietnamese interest in the operation. CTG 115. 4 thought the PCFs were the wrong craft to give the Vietnamese because the boasts were not seaworthy enough for coastal surveillance. This problem plagued the U.S. throughout the entire operation. By the end of 1967, four complete Vietnamese crews had passed the classroom phase of PCF training and they were doing well in the first weeks of operational instruction.




In 1965, MACV estimated that about 70 percent of VC/NVA resupply occurred by seaborne infiltration, mostly by trawler. By mid-1966, MACV estimated that not more than 10 percent of resupply was occurring by sea. And by the end of 1966, there was no longer credible evidence of any recent significant infiltration of troops or supplies by sea. There were trawler infiltration attempts; but from the end of 1966 through 1969, no successful attempts were uncovered.

After the 3 trawlers were destroyed in March 1968, no trawler infiltration attempts were detected for a year and a half. The February-March attempts had been geared to a crisis situation and, therefore, could not be considered routine delivery efforts. Routine seaborne infiltration had been stopped by a combination of circumstances. By mid-1966, Market Time forces had built up enough strength to pose a threat to trawler infiltration. Meanwhile, because of Prince Sihanouk's affinity with the communists event though his country was officially neutral, Cambodia was becoming a VC sanctuary and was being used for the delivery of supplies into MR-3 and-4. After 1965, enemy rear-service groups became satellited on the Cambodian border.

From October 1966 through July 1969, there were between 11,000 and 19,400 tons of military supplies delivered by Chinese ships to Sihanoukville, destined for the VC/NVA in southern SVN (the figures exclude what was siphoned off by the Cambodian army). Because the port of Sihanoukville was opened to these deliveries, and because the VC/NVA knew that the Cambodian resupply route would be ignored by the U.S. for diplomatic reasons, Cambodia replaced the sea as a primary infiltration route to southern SVN. In addition, the Ho Chi Minh trail through Laos had been sufficiently upgraded to take care of resupply needs of northern SVN (figures 10 and 11).

Although large-scale infiltration by sea may have been temporarily deterred, known infiltration-type trawlers had been sighted anchored at Haiphong and conducting routine resupply missions along the coast of NVN. These intra-NVN resupply tasks offered training opportunities for new members of Group 125, and the NVN were assumed to still have the capability for seaborne infiltration.


By spring 1968, the U.S. Navy decided that Market Time had achieved a high degree of effectiveness in preventing trawler infiltrations and determined that CTF 115 should handle more than the operational aspects of Market Time. CT 115 also became an administrative commander in April with the title of ComCosFlot One, with responsibilities for the PCFs and PGs assigned to Market Time.






In May 1968, the southern and central sections of the air tracks were combined; P-3s flew the new section. P-2s generally flew the northern track, although P-3s occasionally made that patrol. The basic track was again moved out to 70 n.mi., and the revisit time set at 5 hours with 5 flights daily. By January 1969, P-3 aircraft were flying a "daisy-chain barrier" in one track from the DMZ to Phu Quoc, maintaining a 5-hour revisit time (Figure 12). The track was still 70 n. mi. offshore, with a permitted deviation of 50 n. mi. on either side. The P-3s generally flew at about 1,500 feet while patrolling.

Because of WestPac DER force level cutbacks in September 1968, CTF 115 assets were permanently cut by one DR. The last Seventh Fleet DER assigned to Market Time completed its assignment in May 1969.

CTF 115 Becomes More Aggressive

The arrival of Capt. Roy Hoffmann and VAdm. Elmo Zumwalt in 1968 marked a change in the philosophy of CTF 1115 and ComNavForV. Market Time and in-country U.S. Navy operations became aggressive. Capt. Hoffmann felt that TF 115 was overcentralized when he arrived and that Market Time should go on the offensive more. Decentralization of TF 115 took place in May, and authority to delegate NGFS missions was given to the CSCs. Since the Market Time air barrier had proven to be the most effective surveillance against seaborne infiltration, a policy was instituted to use the offshore patrol ships during daylight for coastal NGFS and to return them to station for surveillance before dark or when visibility was reduced. These gunships had been generally limited to surveillance with a minor NGFS role. In the third quarter of 1968, more NGFS was conducted by PCFs and WPBs.

The enforcement of restricted zones was emphasized. These zones were promulgated by the South Vietnamese government and enforced by TF 115. They covered high-VC-threat areas off the coast. Some of the zones merely had curfews, while others were restricted to commercial traffic 24 hours a day. The Vietnamese were generally reluctant to enforce these zones; in March 1969, they covered 57 percent of SVN's coastal waters. In 1968, however, the Vietnamese Joint General Staff took control from the province chiefs and emphasized strict enforcement of the zones. Once the areas were clearly delineated and enforced, VC activity became more obvious.

The concept of taking the offensive was expanded in October 1968 with Sea Lords--Southeast Asia Lakes, Oceans, Rivers and Delta Strategy. The original objectives of the operation were to interdict VC infiltration routes from Cambodia along canals from the Bassac River to the Gulf of Thailand; pacify selected Delta waterways; pacify and clear the Bassac River Islands; and harass the enemy. The operation was to combine assets of the Vietnamese naval forces in-country and the 3 U.S. Navy task forces in-country: TF 115, 116 (Game Warden), and 117 (Mobile Riverine Force). Market Time boats relieved TF 116 PBRs on patrol on the lower parts of Delta rivers and made incursions into the canals and rivers of the VC-held areas of western MR-4.




PCFs and WPBs were released for Sea Lords duty without serious detriment to Market Time's coastal surveillance mission because the seaborne infiltration threat had diminished during this period, and because the VNN was taking over patrol responsibility for several areas. The VNN had already assumed responsibility for the 3 coastal radar stations and, on 1 June 1969, took over patrol responsibility for the fourth Coastal Zone.




(U) No trawler infiltration attempt was again detected by Market Time forces until 24 August 1969. The trawler detected that day was tracked until it returned to Chinese waters.

(U) There were to be 14 more trawler infiltration attempts detected by the end of 1970, with MR-4 as their probable destination. One trawler may have successfully infiltrated into An Xuyen Province in August 1970, and another was sunk on 22 November 1970 while attempting to land in Ken Hoa Province. Other trawlers aborted their missions.

(U) The detected trawler infiltration attempts had increased to an average of one a month during 1970, equaling the total number of trawler infiltration attempts detected from the beginning of Market Time in March 1965 through 1969.

(U) The dramatic increase in trawler infiltration attempts and the change in their destination to MR-4 can be explained by the situation in Cambodia. In summer 1969, Prince Sihanouk had placed an embargo on arms shipments to the VC. Although the embargo was temporarily lifted soon after that, it was imposed permanently by late 1969. Sihanouk's ouster in March 1970 and U.S. /SVN cross-border operations in spring 1970 permanently halted the shipments of communist arms through Sihanoukville. The enemy was then forced to find other ways to support his forces in southern SVN. In addition, the first large group of NVA main forces moved into MR-4, placing a further strain on supplies in that area.

NVN Coordinating Units

(C) Several radio stations in MR-4 associated with Group 125 were identified. In addition, a VC rallier reported that, in July 1970, the Communist Party's Central Office for SVN (COSVN) planned to establish alternate supply routes into the Delta area. COSVN had written off Sihanoukville as a supply source. And since MR-4 would be difficult to supply via the Ho Chi Minh Trail, Rear Service Group 962 was reactivated.

(C) Before becoming inactive in December 1966, when munitions began to arrive at Sihanoukville, Group 962 was responsible for receiving, distributing, and storing munitions sent by sea from NVN to MR-4. In addition, members of the 126th Naval Sapper Regiment had been sent by the NVN naval high command to determine feasible offloading points for cargoes delivered by sea. Some of the sappers may have been aboard the trawler destroyed off the coast of Kien Hoa Province in November 1970. Ken Hoa had been mentioned as a target in COSVN directives spelling out enemy strategy for the rest of 1970 and 1971.


The communists in Ken Hoa and An Xuyen Provinces still controlled significant portions of the population in MR-4. And that region's extensive waterway system hindered allied attempts to inhibit seaborne infiltration and coastal transshipment there.

MR-1 and-2 did not depend on Sihanoukville for supplies. NVN expanded the overland route through Laos into Cambodia during te 1970-71 dry season and, by August 1971, it was capable of supporting enemy forces in northern and central SVN as well as east central Cambodia. The enemy did not yet possess the logistical capability to move large quantities of material overland to MR-4. Therefore, he was forced to emphasize seaborne infiltration.

In 1970, more was learned about the VC/NVA coordinating units responsible for seaborne infiltration into MR-1 and-2. The unit (H-44) responsible for gathering intelligence in the coastal areas of Quang Ngai Province requested the seaborne infiltration be stopped because of the many obstacles it was experiencing. The rallier who gave this information said that H-44 moved from the coastal areas inland to handle food production.

A similar unit existed in Binh Dinh (a target for seaborne infiltration in the first trawler infiltration era). The U.S. was aware of another unit in Khanh Hoa Province that could have been tasked with coordination of trawler infiltration attempts. That province was the destination of at least one infiltration attempt. These provinces were still considered by NavForV's intelligence section as possible threat areas in 1970 for trawler infiltration.

Progress of Vietnamization

Vietnamization of Market Time continued during the last half of 1969 and all of 1970. In August 1970, the last 2 WPBs wee transferred to the VNN, signaling the end of the U.S. Coast Guard's participation in Market Time. On 1 September, VNN CTF 213 assumed command of the inner barrier. The last 14 PCRs wee turned over to the Vietnamese on 1 December. The inner barrier under the Vietnamese suffered in 1970 because of inexperience, a lack of standard operating procedures, and improperly used challenge and reply codes.

U.S. Seventh Fleet ships continued to patrol the outer barrier 12 to 40 n. mi. offshore. In addition, another type of barrier was investigated by ComNavForV in early 1970: a coastal radar network able to provide the detection capability of the P-3s after they were withdrawn. These stations would be limited to detecting and tracking contacts. Identification would have to be done by other SVN assets. Since the VNN did not have adequate foul-weather capability, there would be detection capability gaps on either side of the Con Son Island radar site.


S-2s were suggested as replacements for the P-3s. The S-2s would provide a longer reaction time than coastal radar stations and had an identification capability. There were not enough trained Vietnamese available to fly and maintain the S-2s, however, and it would have taken too long to train them.

Penetration Exercises

As part of ComNavForV's review to determine alternative systems to the P-3 barrier, he became concerned about an informed infiltrator's ability to penetrate Market Time's "daisy-chain" air barrier. An informed infiltrator probably could take advantage of the fixed track and launch times of Market Time aircraft. To test this, a series of penetration exercises was run to evaluate the air barrier's detection capability.

PentrEx I was conducted from 25 February to 10 march 1070. In this exercise, 165-foot Seventh Fleet PGs wee used to simulate potential 20-knot infiltrators using ECM to monitor passage of the first flight and transit half-way between pre-selected patrol flights. These units planned to reach the coast of SVN during darkness. Only one of the 9 simulated infiltrators was detected, indicating that the daisy-chain air barrier was highly susceptible to infiltration by an informed infiltrator.

The exercise also led to an admission that the aircraft could not identify contacts at night. They would have to fly only during the day, covering an area that stretched further eastward than that covered by the daisy-chain.

The penetration exercise led to different patrol tracks, with 3 to 4 flights daily. Tracks were chosen randomly each day, with flight paths shifted back and forth up to 20 n. mi. on either side of the track. The aircraft flew in daylight only. Tracks used in fair weather differed somewhat for those used when the weather was bad (Figure 13).

PentrEx II, conducted between 25 April and 10 May, evaluated the new barriers and the detection range of the shore-based radar sites at Cu Lao Re and Poulo Obi. During the exercise, 12 of 19 attempted penetrations were detected. This exercise indicated the soundness of the search-by-day-only concept, and 3 enemy infiltrators were detected during the first 31 days after its inception. The continuation of 4 patrol flights per day would result in a 17 percent reduction in the number of monthly P-3 flights, compared with the daisy chain. In spring 1970, additional reductions were forseen as the Cambodian situation stabilized and as the Market Time inner barrier was returned to full strength. (VNN Market time inner-barrier patrols had been extended to Cambodian waters during cross-border operations.)

PentrEx III (1 July to 31 October) evaluated the fair-weather patrols with 3 flights instead of 4. 38 out of 61 penetration attempts were detected by the air barrier.




Covert Surveillance

(U) During the first trawler infiltration era, Market Time forces used overt surveillance, and the trawlers chose to close the coast after detection. Only 4 of the 12 attempts were aborted. During the second era, when the trawler crew realized it had been detected, it generally aborted its mission. The rules of engagement prohibited Market Time aircraft from engaging suspected North Vietnamese trawlers beyond the 12-n.mi. contiguous zone of the South Vietnamese coast. The North Vietnamese knew they had little to lose, since their trawlers could simply abort once the crews realized they were under surveillance.

(U) Seventh Fleet surface and air assets were tied up when they placed surveillance on the trawlers' homeward journey. MACV thought the enemy would actually be encouraged to make further trawler infiltration attempts if he were convinced international waters were a safe haven. In July, MACV outlined a covet surveillance plant o capture or destroy infiltrating trawlers inside SVN territorial waters. ComNavForV was authorized in August to implement the plan and in November 1970, a trawler was lured into SVN territorial waters and destroyed.

(U) Of the 5 trawler infiltration attempts detected from mid-November 1970 to April 1971 (not including the March 1971 success), covert surveillance was successfully maintained on 2 trawlers; they were destroyed. With policy of full overt surveillance, NavForV analysts determined that the enemy would lose one trawler for every 3 successfully infiltrated. With successful covert surveillance, the loss ratio could be increased to slightly less than 6 trawlers destroyed for every one successfully infiltrate.

SL-8 Trawlers

(U) In February 1971, a larger and more seaworthy type of trawler, the SL-8, was detected attempting to infiltrate SVN. An SL-8 was first sighted in NVN in mid-1970 engaged in intra-NVN coastal resupply mission. Inclusion of the SL-8 in Group 125's inventory signaled a change in enemy tactics and a greater threat to SVN.

(C) The larger trawler had a cargo capacity of 400 tons, compared with 100 tons for most of Group 125's trawlers. The SL-8 was capable of open-ocean operations in any weather short of a typhoon, and it had been observed in a transit of about 5,600 n. mi. without refueling. The distance from Haiphong to MR-4 via the Palawan Passage and return by the South China Sea was about 3,300 n. mi. Market Time air patrols did not cover the Palawan Passage.


Other Enemy Activity

In March, an SL-6 trawler was discovered in An Xuyen Province. The trawler had been stripped and there was nothing to be salvaged. NVN was thought to have had only SL-6 at the time, and it had been last located in Haiphong on 18 December 1970. The March SL-6 presumably eluded Market Time forces some time at the end of December or during the first 2 months of 1971.

After an SL-8 was destroyed in April, no trawlers were detected attempting infiltration until October. With the July implementation of the new Vietnamese inner-barrier concept, the start of visual air reconnaissance and surveillance (VARS), and air strikes against hostile activity in MR-4, reports of MR-4 coastal transshipment drastically decreased and remained low until November 1971.

At the then level of activity, all the basic VC/NVA nonfood requirements for MR-4 could be filled by 2 successful trawler infiltrations a year. At least one of the infiltrators would probably have to be an SL-8.

Cloud Concept

In June, the South Vietnamese initiated their new inner-barrier concept, the Cloud concept. Cloud operations were aimed at preventing enemy coastal transshipment. All units operating in a high-threat area (Figure 14) were placed under the command of the senior officer afloat rather than being allowed to operate independently. This officer coordinated movements to corral junks and sampans near the threat area so that each could be searched.

A typical task unit consisted of one PGM and 4 PCFs/WPBs. Junks supplemented task units in particularly shallow areas. Night operations were emphasized when the likelihood of infiltration was greatest. Cloud operations were not confined to previously delineated inner-barrier situations, although some units still operated individually in low-threat areas. Under the Cloud concept, the inner-barrier units had an increased capability to capture or destroy an infiltrating trawler.

The Cloud concept was necessary because once the coastal radar system was in effect, the warning time for infiltration trawlers would be cut from 2-3 days to 2-3 hours. It probably would be the task of inner-barrier craft to intercept the trawler, and task units were needed to successfully engage a trawler. Starting in July, one or 2 radar stations a month were turned over to the VNN (Figure 15).

The success of the first cloud task unit led to the formation of 8 more. In addition, there were more combined VNN/SVN army operations and improved statistics for detections and inspections.






Once the Cloud concept was started, the larger fleet command ships were assigned to cover high-threat areas seaward of the task units. Their heavy guns were available to back up a task unit during a trawler infiltration attempt.

New Air Patrols

Although the May 1971 Market Time Final Report suggested the enemy's possible use of the Palawan Passage, the new track (advancing patrol) that Market Time aircraft were flying in June did not take that threat into consideration. The advancing patrol (Figure 16) was planned to take advantage of intelligence indicating MR-4 as the target of infiltrating trawlers. By the end of 1970, there was no indication that the Palawan Passage had been used as an infiltration route. The advancing patrol was planned around the known route, which forced trawlers into the choke point between the Dangerous Ground and SVN. The advancing patrol replaced the tracks that had been flown in 1970.

The advancing patrol was useful when there was information available about an infiltrator's route and destination. An informed infiltrator could generally avoid air patrols at little or no risk. But if intelligence was correct in pointing to MR-4 as the destination, and if the trawlers approached the coast of SVN through the choke point between the Dangerous Ground and SVN, there was no way a trawler could avoid being detected and tracked by the advancing patrol. One aircraft flying 8 hours a day in the SVN/Dangerous Ground gap could detect and track all infiltrating trawlers enroute to MR-4 with nearly 100-percent accuracy.

The advancing patrol was designed for a 150-knot aircraft speed of advance (SOA), a 15-knot infiltrating trawler SOA, an 8-hour patrol followed by a 16-hour no-patrol period, a radar sweep width of 60 n. mi., and a total track length of about 1200 n.mi. The aircraft swept a rectangle 215 by 240 n. mi. A 15-knot infiltrating trawler could not transit this rectangle during the no-patrol period.

The advancing patrol was modified in October by extending coverage 15 n. mi. eastward, based on the 28 October trawler detection. The detection suggested the possibility of an informed infiltrator's trying to evade between the patrol's eastern boundary and the




Dangerous Ground. For added protection against the possibility of trawlers transiting the Palawan Passage, VP aircraft conducted a patrol around the southern portion of SVN about 15 days a month.

(U) In early 1972, Market Time analysts determined that infiltrating trawlers probably began to use a new route in December 1971. This route indeed took the trawlers through the Palawan Passage or the Dangerous Ground. New air patrols were begun in February to cover the Palawan Passage, the Dangerous Ground, the Dangerous Ground/SVN gap, and the South China Sea shipping lanes (Figure 17).


(C) In 1971, there was an effort to pass information from photoreconnaissance flights to Market Time. Group 125 trawlers were located at anchor and their port facilities photographed. It was then that the most reliable inventories of Group 125's assets were compiled (see Appendix F).

(C) Each time a photograph revealed that a trawler had left port, the information was passed to a submarine stationed off the coast of China. If the trawler passed through the Hainan Straits and headed south, the submarine would alert the Market Time air barrier.

Change in Priorities

(U) Priorities of Market Time air patrols were changed during 1971. In the past, every contact had been "rigged." This helped fulfill the TF 72 surveillance mission in the South China Sea, but it detracted from the Market Time effort since large contacts were never infiltrating North Vietnamese trawlers. While the aircraft were busy investigating these larger contacts, the trawlers could have slipped through the air barrier. In 1971, aircraft on Market Time patrol were ordered to investigate only smaller contacts.

(C) The increase in trawler infiltration attempts was observed after the change in priorities of Market Time air patrols, new tracks, and the coordinated effort to bolster these patrols by photoreconnaissance information and a submarine. More trawlers were detected between October 1971 and April 1972 than during any previous 7 months. It is impossible to determine whether NVN was suddenly sending more trawlers, or whether the change in U.S. priorities led to more detections. It is almost certain that U.S. forces were detecting a much higher percentage of trawlers attempting infiltration than in the past.

Enemy Seaborne Infiltration and Transshipment Activity

(U) Beginning in October 1971, an enemy tactic was used that had not been observed since February 1968--that of saturating the coastal surveillance barriers. In October, December, February, March, and April, 3 to 4 Group 125 trawlers were dispatched to SVN over




10 to 25 days. The last of these attempts to flood the coastal surveillance system ended on 24 April when the VNN destroyed a trawler in the Gulf of Thailand.

There were low-level intelligence reports indicating that the communists might be meeting some of their resupply requirements in MR-4 through sea infiltration. There was also a report that supplies were loaded onto ships of unknown nationality in NVN and offloaded into fishing boats of up to 20 tons, 30 n. mi. offshore in the Gulf of Thailand. The supplies were then shipped to the southern and western coasts of An Xuyen, where they were transferred into motorized sampans and moved inland.

There were other low-level intelligence reports of coastal transshipment in the Cambodia/SVN border re. Enemy concentrations in the SVN border provinces and continued engagements in those areas suggested the existence of supply caches in southern Cambodia. Most of the reports indicated the material had been infiltrated by overland routes through Cambodia. The possibility of sea infiltration into that country was confirmed by the prisoners captured from a trawler destroyed in April. The trawler's crew had been given orders to land in Cambodia if they could not safely land in Vietnam.

MR-4 was most vulnerable to coastal transshipment because of extensive areas under VC control. In addition, no-boat zones were violated with impunity. These were the best fishing areas; the Vietnamese only nominally punished violators of restricted zones, and the fishing boats provided a good cover for transshippers.

Status of Vietnamization

In June, VARS was begun to check on the performance of patrol craft and to provide intelligence on suspicious coastal transshipment. The VARS mission was soon taken over by the SVN air force, although it was not as effective as its U.S. counterpart.

By July, the VNN had only 4 ships (DERs and WHECs) capable of individually intercepting and sinking trawlers. Only 2 of the ships were on station.

CosFlot Five operated 34 PCFs on the rivers of the Delta in May. This was 33 percent of the PCF inventory and 23 percent of the total inventory of craft originally procured for the inner barrier. NavForV analysts suggested these PCFs be returned to Market Time. In August, with these added assets, the VNN established the Southern Surveillance Zone, headquarters at Nam Can. Market Time coverage of An Xuyen Province had suffered because inner-barrier craft had to patrol too far away from their bases at An Thoi or Vung Tau to adequately cover the area. With a base at Nam Can, the heavily VC-infested area would come under surveillance by Market Time patrols.

A series of unannounced penetration exercises conducted by TF 115 ships was started in September. The results of these exercises indicated that training was going too slowly. In the first 10 penetration exercises, there were only two interceptions made in satisfactory


time. The VNN was having command-and-control problems with coordination throughout the entire coastal surveillance system. The hope was that the radar system would be an effective command-and-control instrument for tracking and managing patrol craft as well as for detecting infiltrators. There is some question as to why the responsibility to observe Cloud patrol effectiveness could not be the burden of highly motivated officers in tactical command instead of the radar stations. These stations were planned to give maximum radar coverage against infiltrators approaching the coast from seaward but not to track small craft sailing inshore waters.

There were further changes in the coastal surveillance operation under the VNN in October. The VNN coastal surveillance commander, CTF 213, was replaced by a DCNO for Sea Operations with coastal zone commanders as task force commanders who had operational control of all coastal surveillance assets in their areas of operations. This administrative change implied the VNN was interested in dealing with the problems of each surveillance zone instead of directing an inflexible operation that did not take into account the unique problems of each of the 5 surveillance areas along the SVN coast. But because of the initial lack of centralization, coordination problems continued.

By November, the improvement in VNN coastal surveillance operations had leveled off. This resulted partly from unusually severer weather since the latter part of October. The loss of VARS and other air surveillance because of the withdrawal of some U.S. aircraft contributed to the leveling off and, in some cases, the decline of coastal surveillance effectiveness. Apparently, the VNN also lost some of its motivation for aggressive patrols during the last quarter of 1971. There was also no progress in developing SVN air force capability conduct maritime patrols by the end of 1971.

By spring 1972, the VNN coastal patrol craft fleet consisted of 103 PCFs and 26 WPBs. There were 181 armed junks and 26 ferro-cement coastal raiders in the 20 coastal groups along the coast, 28 more were under construction, and 50 more were planned for future use. The South Vietnamese averaged more than 4 ships per day on station in the outer barrier, compared with the 2 ships or less per day on station in the outer barrier 6 months earlier.



After a trawler was sunk on 24 April 1972 in international waters in the Gulf of Thailand, no other steel-hulled trawler infiltration attempts were detected by Market Time forces. This was the first incident in which friendly forces did not wait to fire until the trawler was within waters contiguous to SVN.

During mid-1972, a new infiltration organization, Group 950, was established by NVN to replace Group 125. Group 125 trawlers were probably used for resupply within NVN with the possibility of being called for infiltration missions should the need become critical. Group 950 had at least 10 fishing-type trawlers, either built or bought in SVN. These trawlers were legally registered in SVN and had the necessary papers for operating within SVN territorial waters.

During the 1972 NVN spring offensive into SVN, the VC/NVA successfully supplied their forces. While there was no indication that coastal infiltration or transshipment constituted an important source of supplies then, unevaluated reports indicated a significant amount of supplies were being brought to the communists by sea. The supplies were probably moved by small fishing vessels because of Market Time air surveillance and the blockade of Haiphong. These vessels may have belonged to Group 950.

Although the trawlers of Group 125 used Hainan Island, it is possible that the mining of Haiphong upset NVN's plans to use Group 125 trawlers for infiltration missions. If Group 125 depended on Haiphong as its major port facility, the NVN would have had to develop new tactics for seaborne infiltration after the mining. It is also possible that the 24 April sinking of an SL-4 prompted the change in NVM tactics, since the South Vietnamese were obviously not going to wait for a trawler to reach SVN's contiguous waters before firing.

Progress of Vietnamization

Between April 1972 and the cease-fire in January 1973, Vietnamization of Market Time was completed with the turnover of 3 WHECs to the VNN in June and July 1972. By 15 August land radar sites and one radar ship were operating under VNN control. U.S. surface participation in coastal surveillance was officially ended with the discontinuance of CTF 115 in December.

U.S. Navy air assets were still being flown for Market Time in 1972. Observation aircraft were withdrawn in March and April, but P-3s were still flown. During the height of the NVN offensive, as many as 20 VP sorties were flown daily in the South China Sea and the Gulf of Thailand, with the major portion of these flights dedicated to Market Time. By September, there were 4 P-3 flights a day flown for Market Time and, in January, P-3s flew 2 daily sorties for Market Time.


As the U.S. Navy was winding down and terminating its part of coastal surveillance operations, evaluations were made of the VNN coastal surveillance system. Several series of penetration exercises were performed. In August, the VNN identified 50 of 55 units simulating NVN trawlers; 75 percent of these ships were intercepted.

Although the system seemed to be improving, the SVN coastal surveillance operation had many problems. In particular, the VNN still depended on U.S. maritime patrols to detect enemy ships. VARS flights were insufficient after U.S. observation aircraft were withdrawn, and the SVN air force was sent on higher-priority missions during the NVN spring offensive. The coastal radar sites were generally isolated and inaccessible, and difficult to support. There were not many people available with both the morale or talent needed to be officers in Command of the radar stations.

The VNN were plagued with command and control problems, a lack of motivation, and a lack of trained personnel. All of these problems resulted in a lack of aggressiveness in the patrols and all phases of the coastal surveillance mission: detection, identification, and interception.



No complete understanding of the effectiveness of Market Time is possible until information is available revealing the enemy's assessment of the operation. No adequate measure of effectiveness was ever developed against coastal transshipment or junk infiltration. Although there is a significant amount of information available on NVN trawler infiltration attempts, this material was generally collected from U.S./Vietnamese observations and not enemy records.

But despite the lac of enemy records attesting to the success or failure of Market Time, some conclusions can be drawn:

  • Market Time was a deterrent to trawler infiltration; but it did not detect every trawler infiltration attempt.
  • VP aircraft were the most essential ingredient of Market Time.
  • The rules of engagement were too restrictive in not permitting Market Time forces to engage known infiltrating trawlers in international waters.
  • Divergent air bases and the use of 3 different types of aircraft for the first few years of Market Time resulted in scheduling problems and less effective patrols than were later developed.
  • PCF/WPB bases were too far apart in southern SVN. Until a base was established at Nam Can in 1971, the tip of An Zuyen Province was virtually unpatrolled; this region had been a traditional area of VC coastal transshipment.
  • Not until the Pentrex exercises was it recognized that air patrols could not identify contacts at night and that the air barrier was susceptible to penetration by an informed infiltrator. As a result of those exercises, aircraft flew during daylight only and farther east than they had been doing; they flew the new tracks at random, and shifted back and forth up to 20 n. mi. on either side of the track. Subsequent exercises using the new flight patterns confirmed the soundness of the new air barrier; and, as a matter of fact, 3 infiltrators were detected within the first month after its inception.
  • The Cloud concept (task unit operations in the inner barrier) was sound in theory but implemented far too late.
  • Market Time aircraft should have concentrated their efforts on smaller contacts much earlier than 1971, since large contacts would probably not have been NVN trawlers. By 1968, there was a clear picture of the size of the trawlers that could be expected to attempt infiltration.



Jane's All the World's Aircraft, S. Low, Marston and Co., Ltd, London, 1961/1962, 1962/1963, 1968/1969

MACV, Ser. 0076, "Report of Recommendations Pertaining to Infiltration into South Vietnam of VC Personnel, Supporting Materials, Weapons and Ammunition (U)," Secret, 15 Feb 1964 (Buckley Report)

Office of the Chief of Naval Operations, Naval History Division (Op-09BH), "History of Naval Operations, Vietnam, Volume I -- 1946-1964 (U)," Secret Jun 1974; "History of U.S. Naval Operations, Vietnam, Volume I -- 1964 (U)," Secret, Feb 1970; draft "Volume III -- 1965-1067 (U)," Secret, Feb 1971

CinCPac Command History, Top Secret, published annually from 1964 through 1972

MACV Command History, Top Secret, published annually from 1964 through 1972 (the last volume covers Jan 1972 through March 1973)

Naval Advisory Group, MACV, Historical Review, Secret, monthly Mar 1965-Mar 1966

Commander, Seventh Fleet Msg. 101056Z Apr 1965, "Market Time Staff Study (U)," Secret

U.S. Coast Guard diaries and summaries of Market Time activities, published monthly or weekly, Secret to Confidential, Mar 1965-Dec 1971

CTF 71, Operation Order 307B-65, DTG: 020630Z Jun 1965, Secret/NoForn

Commander, Coastal Surveillance Force, Operation Order 10-65, DTG: 090100Z Jul 1965, Secret

Commander, Patrol Force Seventh Fleet, Flt. Ltr. Ser. 0051, "Final Market Time Report (U)," Secret, 29 Jul 1965

U.S. Intelligence Board, USIB Memorandum, "Infiltration and Logistics--South Vietnam (U)," Secret, 28 Oct 1965

Defense Intelligence Agency, Southeast Asia Military Fact Book, Secret, Oct 1965 through Sep 1970

U.S. Seventh Fleet, Monthly Reports, 1965-1966, Secret/NoForn

CinCPac Scientific Advisory Group, WP 4-66, "Summary of Market Time Activities for Period 1 August through 31 December 1965 (U)," Secret, Jan 1966

CinCPacFlt, Pacific Area Naval Operations Review, Secret, Monthly, Jan 1966-Jul 1968 and Fleet Operations Review, Secret, Monthly, Aug 1968-Jun 1970, quarterly July-Sept 1970 to present


U.S. Naval Ordnance Laboratory, NOLTR 66-25, "Small Craft Catalog (U)," Confidential, 1 Mar 1966

JCS, NASVA Data Base, Confidential, Mar 1966 through July 1971

Commander, Coastal Surveillance Force, Operation Order 201-YR, DTG: 010400Z Apr 1966, Confidential

U.S. Naval Forces, Vietnam Monthly Historical Summaries and Supplements, Secret to Confidential, Apr 1966 through Dec 1971

MACV, Combined Intelligence Center Vietnam Special Report SR 67-002, "VC/NVA Gunrunners ()," Confidential, 9 August 1966

ComNavForV, Ser 00133-66, "Estimate of Sea Infiltration (U)," Secret, 2 Sep 1966

ComNavForV, Assistant Chief of Staff for Intelligence, enclosure to Ser 00194-66, "Sea Infiltration into South Vietnam ()," Secret, 12 Oct 1966

CinCPac Scientific Advisory Group, WP 26-66, "Summary of Market Time (March 1965 through September 1966) (U)," Secret/NoForn, downgraded to Confidential, 25 Nov 1966

Center for Naval Analyses, OEG Study 706, "Market Time: Countering Sea-Borne Infiltration in South Vietnam (U)," Confidential, 20 Dec 1966

ComNavForV, Memorandum for the Assistant Chief of Staff, Operations, "Sea Infiltration into Southern Quang Ngai and Northern Binh Dinh ()," Secret, 11 Apr 1967

ComNavForV, Ser 0092-67, "Sea Infiltration ()," Secret, 25 Apr 1967

Ismay, Capt. A., interview with, conducted by D.C. Allard, O.P. Fitzgerald, and Lt. M. Kelly in the Office of 91-E, Unclassified, 6 June 1967

CinCPac, "Infiltration Study in Support of Infiltration/Interdiction Conference (U)," Secret, 24 July 1967

Commander, Coastal Surveillance Force, Operation Order No. 201-67, DTG: 150401Z Aug 67, Confidential

MACV, MACJ32, "Market Time Study Group Report (U)," Secret downgraded to Confidential, 6 Sep 1967

ComNavForV Staff Study, "Market Time Requirements ()," Secret, 8 Sep 1967

Hurlburt, Lt. J.S., U.S.N., end of tour debrief, Unclassified, 8 Dec 1967

Venzke, Cdr. N.C., USCG, end of tour debrief, Confidential, 27 Mar 1968

Center for Naval Analyses, Memorandum for Director, OEG, (OEG) 0263-68, "Effect of an Infiltrator Detection Capability Upon Market Time Effectiveness (U)," Confidential, 23 Apr 1968


CinCPac, "Infiltration Study (U)," Secret, 29 May 1968

Center for Naval Analyses, Memorandum for Director, OEG, (OEG) 00373068, "Trip to South Vietnam, May 1968; Report of (U)," Secret, 28 Jun 1968

Central Intelligence Agency, Intelligence Memorandum ER IM 68-84, "Cambodia's Role in the Movement of Arms and Ammunition to the Vietnamese Communists ()," Secret, Jul 1968

Center for Naval Analyses, Memorandum for Director, OEG, (OEG) 0540-68, "Market Time Capability to Detect Friendly Merchant Ships (U)," Confidential, 1 Oct 1968

ComNavForV, Ser. 0638, "Special Narrative Summary of ComNavForV Operations for the Third Quarter CY 1968 ()," Confidential, 9 Oct 1968

ComNavForv, RN-3, "Market Time Effectiveness in IV Corps (U)," Confidential, Dec 1968

ComNavForV, WP-3, "Market Time Air Barrier Documentation Analysis (U)," Confidential, Jan 1969

Commander, Coastal Surveillance Force (CTF 115), Operation Order 201-69, DTG: 28001Z Feb 1969, Confidential

Venzke, Cdr. N.C., USCG, interview with, conducted at Coast Guard Headquarters in Washington, D.C., by the Vietnam Writing Section, Naval History Division, Office of the Chief of Naval Operations, Secret, 28 Feb 1969

Center for Naval Analyses, Memorandum for Director, OEG, (OEG) 0155-69, "Market Time Aircraft Barrier Operations Against Intelligent Infiltrators (U)," Confidential, 24 Mar 1969

ComNavForV, WP-8, "Analysis of Market Time Inshore Barrier (U)," Confidential, Mar 1969

Westwood Research, WR-119-B, Final Report, "A Review of U.S. Navy Experiences in Establishment and Conduct of South Vietnam Inshore Coastal Patrol: Operation Market Time (U)," Confidential, May 1969

ComNavForV, WP-6, "A Market Time Sampling Model," Unclassified, Jun 1969

McGhee, LCdr. K.D., USN, end-of-tour report, Unclassified, 27 July 1969

ComNavForV, Operation Order 201-70, Ser. 0491, Confidential, 18 Sep 1969

Nicolson, Capt. R.E., USN end-of-tour report, enclosure to ComNavForV Ser. 00256-69, Secret, downgraded to Confidential, 7 Nov 1969

ComNavForV, Ser. 0014-70, "Covert Surveillance of NVN Infiltration Trawler ()," Secret, 24 Jan 1970


ComNavForV, "Market Time II (U)," Secret, Feb 1970

ComNavForV, Memorandum for the Commander, U.S. Naval Forces, Vietnam, "Proposal for a More Effective Air Barrier Utilizing Current Market Time VP Forces ()," Secret, 10 Apr 1970

ComNavforV, Memorandum for the Commander, U.S. Naval Forces, Vietnam, No. 00153-70, "Comparison of CTF 72 Proposed Tracks with Current Market Time and DMZ/Luzon Proposed Barrier ()," Secret, 12 Apr 1970

Center for Naval Analyses, OEG Study 738, "Market Time Effectiveness (U)," Secret, May 1970

Commander, Coastal Surveillance Force, Operation Order 201, DTG: 202335Z Sep 1970, Confidential

ComNavForV, RN-36, "A Re-evaluation of the Market Time Inner Barrier (U)," Confidential, Sep 1970

ComNavForV, Memorandum for the Special Assistant for Operations Analysis, "Seaborne Infiltration (U)," Confidential, 7 Dec 1970

Central Intelligence Agency, Intelligence Memorandum ER IM 70-188, "Communist Deliveries to Cambodia for the VC/NVA Forces in SVN, December 1966-Apr 1969 ()," Secret, Dec 1970

ComNavForV, WP-16, "Market Time Air Barrier Modification ()," Secret, Dec 1970

Naval Reconnaissance and Technical Support Center, Selected Photo Interpretation Analyses, "North Vietnamese Infiltration Trawlers (U)," Secret, Mar 1971

Assistant Chief of Staff for Intelligence, U.S. Army, "The Role of Cambodia in the NVN-VC War Effort--1964-1970, Volume I (U)," Top Secret, 13 Apr 1971

Defense Intelligence Agency, Defense Intelligence Digest, Volume 9, Number 4, "North Vietnamese Sea Infiltration Attempts Continuing ()," Secret/NoForn, Apr 1971

ComNavForV, "Memorandum for N-3, "Market Time Review; Deployment of Surface Forces (U)," Confidential, 14 May 1971

ComNavForV, "Market Time Review 1971--Final Report (U)," Confidential, 30 May 1971

ComNavForV, "Infiltration and Transshipment Studies (U)," Confidential, 30 May 1971

ComNavForV, RN-39, "An Examination of the Enemy's Cost and Probability of Penetrating the Market Time Barrier under Overt and Covert Surveillance Policies by Market Time Forces (U)," Secret downgraded to Confidential, May 1971

ComNavForV, enclosure to ltr. ser. 0099-71, "Market Time Air Coverage (U)," Secret, 14 Jun 1971


ComNavForV, RN-40, "The Contribution of the Market Time Surface Barrier to Overall Market Time Forces Probability of Trawler Detection (U)," Secret, downgraded to Confidential, Jul 1971

Central Intelligence Agency, Intelligence Memorandum ER IM 71-156, "North Vietnamese Sea Infiltration of Military Supplies into South Vietnam ()," Secret/NoForn, Aug 1971

Fleet Intelligence Center, Pacific, "Vietnam Infiltration Trawler Identification Guide, Supplement 1, Second Edition (U)," Secret, Aug 1971

Schreadley, Cdr. R.L., USN, "The Naval War in Vietnam, 1950-1970," U.S. Naval Institute Proceedings, Naval Review, 1971

Sullivan, Cdr. J.G., USN, end-of-tour report, Confidential, 31 Jan 1972

Center for Naval Analyses, OEG Study 765, "Effectiveness of Market Time after Vietnamization (U)," Secret, 15 Mar 1972

ComNavForV, Ser. 0369, "Maritime Resupply Threat Analysis and Area Study (U)," Confidential, 22 Apr 1972

CTF 115, Ser. 001, enclosure to "Action Report (U)," Secret/NoForn, 14 Jul 1972

ComNavForV, "Market Time Review 1972 (U)," Secret, 24 June 1972

Kolstad, Capt. T.I., USN, end-of-tour report, Confidential, 21 Aug 1972

Center for Naval Analyses, Memorandum for Director, Surface Warfare Division (Op-32), "ComNavForV Market Time Review 1972 (U)," Secret, 8 Sep 1872

ComNavForV, "Crew of North Vietnamese Infiltration Trawler 645; Interrogation of (U)," Confidential, 6 Oct 1972

Hooper, VAdm. E.B., USN ret, "Mobility, Support, Endurance," Dept. of the Navy Naval History Division, Unclassified, 1972

Blackburn, VAdm. P.P., USN ret., interview with, conducted at Hilton Head, S.C., by O. Fitzgerald of the Operational Archives Naval History Division, Office of the Chief of Naval Operations. For Official Use only, 26 Nov 1973

Albrecht, G., "Weyer's Warships of the World, U.S. Naval Institute, 1973"

Central Intelligence Agency, Report No FIR-311/01873-74, "Organization, Function, Location, Strength, and Chinese Assistance to the 125th Seaway Transportation Regiment of the North Vietnamese Navy High Command (C)," Confidential, 26 June 1974

ComNavForV, RN-23, "An Estimation of the Detection Capability of the Market Time 'Loop' Surveillance Patrols (U)," Confidential, undated

CNA Research Contribution, "Game Warden (U)," Secret, in preparation


Appendix A
Characteristics of VNN PCE and PGM

This appendix gives the characteristics of the Vietnamese PCEs (figure A-1) and PGMs (figure A-2) committed to the VNN Sea Force for Market Time patrols.


185 feet
34 feet
9 feet
12.5 knots
    Armament: 1--3"/50
    Crew: 93
FIG. A-1: VNN Patrol Escort (PCE)
Length: 100 feet       Endurance: 1,000 n. mi. at 12 knots
Beam: 21 feet       Armament: 1--40 mm. single-mount Mk 3
Draft: 7 feet         2--50-caliber
Speed: 17 knots         2--20 mm. single-mount Mk 10 Mod 2


1 Officer, 14 Crew          
FIG A-2: Patrol Motor Gun Boat (PGM)


Appendix B
Characteristics of U.S. Surface Craft Assigned to Market Time


This appendix describes and compares the 7 major U.S. Navy/U.S. Coast Guard surface craft committed to Market Time.


Table B-1

Comparison of Market Time Surface Patrol Craft Characteristics

Length 50 ft 82 ft 306 ft 173 ft 144 ft 311 ft 185 ft
Speed (kt.)
    Cruise 10-12 12.5 10.5 10 10 11 14
    Dash (max) 23 17 20 14 14 19 40
Draft 5 ft 6 ft 15 ft 14 ft 11 ft 14 ft 9 ft 6 in
    Officers 1 2 16 6 4 13 4
    Enlisted 5 9 185 71 35 140 27
    5"/38           1 (S)  
    3"/50     2 (S)       1 (S)
    40mm.       1 (S)     1 (S)
    50 caliber 1 (T)
1 (S)
5 (S)       6 (S) 2 (S)
    20mm.         1 (T)    
    81mm. mortar 1 1       2  
    Endurance 400 n.mi radius
at 10 kt.
1,000 n.mi. 13,350 n.mi. 3,300 n.mi.
at 10 kt.
1,300 n.mi.
at 13.5 kt.
2,200 n.mi.
at 10 kt.
22,000 n.mi.
at 11 kt
8,000 n.mi.
at 19 kt.
500 n.mi.
at 40 kt.
1,900 n.mi.
at 14 kt.
    Seaworthy IB--poor
OB--primary OB
ship until WHECs
began to replace it
in 1967
OB OB OB--primary OB
ship by 1969
Key: Twin (T).
  Single (S).
  Inner barrier (IB).
  Outer barrier (OB).
Source: Staff Study--NavForC "Market Time Requirements," 8 Sep 1967


Length: 50 feet
Beam: 13 feet
Draft: 5 feet
Speed: 23 knots
Endurance: 400 n.mi.
Radius 10 knots
Crew: 1 Officer, 5 Enlisted
Armament: 1--50-caliber twin machine gun
1--50-caliber single machine gun
1--81 mm. mortar
URC-58 (SSB)
PRC-10 (10 n.mi. range)
PRC-2 (35 n.mi range)
Radar: DECCA range (24 n.mi max.)
Wooden junk (2 n.mi.)
PFC (SWIFT) silhouette
Length: 82 feet
Beam: 18 feet
Draft: 5 feet, 11 inches
Speed: 18 knots
Endurance: 1,000 n.mi.
Crew: 2 Officers,
9 Enlisted,
1 VNN (liaison)
Armament: 4--50-caliber single machine gun
1--50-caliber single machine gun
        O/U 81 mm. mortar
URC-58 (SSB), URC-45, URC-7,
PRC-10, PRC-25, UHF
Radar: Frequency 9375 (X-band)
Range: Steel hull, 17 n.mi.
            Swift, 8 n.mi.
            Wooden junk, 3-4 n.mi.
Remarks: Normally deployed on a 5-day patrol. Excellent seakeeping characteristics; fathometer
WPB silhouette


Length: 306 feet
Beam: 36.5 feet
Draft: 15 feet
Speed: 20 knots
Endurance: 13,350 n.mi. at 10 knots
Crew: 16 Officers, 185 enlisted
Armament: 2--3"/50 singles
4 HF
2 VHF (AM)
SPS-4 (surface)
SPS-28 air search
Remarks: Primary off-shore patrol ship. Has excellent command and control facilities. Can be used as mother ship for WPB/PCF to extend range and endurance of these small craft
DER silhouette


Length: 173 feet
Beam: 36 feet
Draft: 14 feet
Speed: 14 knots
Endurance: 3,300 n.mi. at 10 knots
Crew: 6 Officers, 71 enlisted
Armament: 1--40mm. single
1 HF, 2 UHF
Radar: SPS-5C (S land)
Sonar VOS mine-hunting
Remarks: Primary mission--minesweeping.
In addition to Market Time patrol, has bee used for underwater search. Limited in speed, electronic equipment, and armament.
MSO silhouette
  Length: 144 feet
  Beam: 28 feet
  Draft: 11 feet
  Speed: 14 knots
  Endurance: 1,300 n.mi. at 13.5 knots
2,200 n.mi. at 10 knots
  Crew: 4 Officers, 35 enlisted
  Armament: 1--20mm. twin-mount
  Remarks: Excellent maneuverability; short endurance. Wood construction. Limited communications and armament.
MSC silhouette


Length: 311 feet
Beam: 41 feet
Draft: 14 feet
Speed: 19 knots
Endurance: 22,000 n.mi. at 11 knots
8,000 n.mi. at 19 knots
Crew: 13 Officers, 140 Enlisted
Armament: 1--5"/38 mount w/Mk 52 FC director
6--50-caliber single machine gun
2--81mm. mortars
6--Mk 44 torpedoes
4 HF
1 FM
Radar: SOS-1 or 11 sonar
SPS-29 air search radar
SPS-23 surface-search radar
Complete communications and on-line crypto facilities
Mk 26--FC radar
WHEC silhouette
  Length: 165 feet
  Beam: 23.6 feet
  Draft: 9.6 feet
  Speed: 10-14 knots (patrol)
40 knots (dash)
  Endurance: 500 n.mi. at 40 knots
1,900 n.mi. at 14 knots
  Crew: 4 Officers, 27 Enlisted
  Armament: 1--3"/50 single
1--40mm. single
2--50-caliber single machine gun
  Radar: SPG-50
PG silhouette


Appendix C
Characteristics of VP Aircraft Assigned to Market Time

This appendix describes the 3 VP aircraft used in Market Time. The characteristics discussed are those relevant to the coastal surveillance mission of these aircraft.


Table C-1
P-2H Neptune (Lockheed)

ASW patrol

    Combat range    
          Average cruising speed (knots) 174
          Cruising altitude (feet) 1,500
    Combat radius (n.mi.) 1,050
          Average cruising speed (knots) 174
    Search time/altitude (hours/feet) 3.0/1,500
    Search speed (knots) 162
    Crew -- 7    
    Radar -- APS-20    

Cable C-2
P-5B Marlin (Martin)

ASW patrol

    Combat range (n.mi.) 2,070
          Average cruising speed (knots) 149
          Cruising altitude (feet) 1,500
    Combat radius (n.mi.) 830
    Mission time (range) (hours)a 13.93
          Average cruising speed (knots) 149
    Crew -- 8  
    Radar -- APS-80  

aTotal time for climb and cruise.


Table C-3
P-3A Oriona (Lockheed)

ASW basic mission

    Combat range (n.mi.) 3,700
          Average cruising speed (knots) 310
          Cruising altitude (feet) 15,000
    Combat radius/mission time (n.mi./hour) 1,400/12.15
          Average cruising speed (knots) 308
    Search time/altitude (hours/feet) 3.0/1500
    Search speed (knots) 194
    Crew -- 12
    Radar -- APS-80

aThe P-3B, also used in Market Time, is similar to the P-3A.


Appendix D
Market Time Surface Craft Force Levels

This appendix deals with Market Time surface craft force levels. Information available covers April 1966 through June 1971. Figures D-1 and D-2 are based on tables D-1 and D-2.

The force levels for surface craft do not distinguish between routine coastal surveillance operations and Market Time participation in special operations such as Sea Lords. RAdm. Roy Hoffmann, a former CTF 115, indicated that PCF/WPB assets used in riverine operations beginning in late 1968 involved 40 percent (at most) of the available inner-barrier patrol craft.

The sharp increase in the number of small ships/boats assigned to Market Time in 1966 reflects the buildup phase of the operation. The sharp decline of U.S. small ships/boats in 1970 and the concurrent increase in Vietnamese forces reflect Vietnamization.

The discrepancy between the small ships and boats assigned and those actually used in Market Time can be accounted for by:

  • Upkeep.
  • Use of boats for training.
  • Foul weather.
  • Inability of PCFs to remain away from their bases for more than 36 hours.

The peak in the numbers of Vietnamese large ships assigned to Market Time in the fourth quarter of CY 1966 probably reflects an error in either the NASVA (Naval Surveillance Activity in Vietnam) data base or the program.


FIG. D-1: Average Number of Large USN/USCG/VNN Forces Assigned and Employed (By Quarters)


FIG. D-2: Average Number of Small USN/VNN Ships and Boats Assigned and Employed (By Quarters)


Table D-1

Average Number of VNN Surface Forces Assigned/
Average Number Employed
(By quarter)

  2/66 3/66 4/66 1/67 2/67 3/67 4/67 1/68 2/68 3/68 4/68
LSIL 1.36 0.77 0.97 0.38 0.35 0.15 0.15 0.15     0.27
  0.30 0.13 1.04 0.20 0.24 0.05 0.08 0.05     0.14
LSM                     0.15
LSSC   0.01                  
LSSL 3.20 3.84 24.95 0.39 0.15 0.30   0.07 0.38 0.39  
  1.02 1.07 1.32 0.15 0.10 0.27   0.05 0.18 0.20  
LST 0.08                    
MSC 1.69 1.91 1.53 1.26 0.67 0.95 0.70 0.70 0.82 1.05 1.59
  0.49 0.47 0.62 0.69 0.43 0.72 0.39 0.46 0.40 0.59 0.90
MSO   0.08                 0.08
    0.01                 0.00
PC 1.66 0.34   0.38 0.49     0.20 0.87 0.46  
  0.57 0.06   0.23 0.39     0.09 0.33 0.29  
PCE 2.80 4.03 2.80 3.02 2.13 2.30 2.60 2.57 2.49 2.28 2.63
  0.83 1.32 1.61 2.13 1.65 2.09 1.78 1.70 1.66 1.24 1.49
PCF 0.08 0.30 1.07     0.08       1.75 6.27
  0.01 0.04 0.46     0.00       1.18 2.50
PG           0.00 0.02        
            0.05 0.02        
PGM 8.27 10.62 7.07 7.88 6.80 7.93 8.98 8.36 10.14 9.93 10.11
  2.51 3.57 4.55 4.03 4.70 5.56 5.65 4.82 6.19 5.97 6.84
  1/69 2/69 3/69 4/69 1/70 2/70 3/70 4/70 1/71 2/71          
AKL       0.15   0.23          
        0.09   0.15          
DER                   0.56  
HSC       0.08              
LSIL       0.08 0.78            
        0.05 0.77            
LSM       0.08              
LSSL     0.24 0.39   0.40          
      0.14 0.22   0.26          
LST     0.08                
MSC 1.54 1.38 1.10 1.46 1.00 1.07 1.16 0.92 0.62 0.83  
  0.99 0.59 0.74 0.92 0.72 0.47 0.93 0.43 0.38 0.32  
MSO             0.15        
PB             19.68 24.58 11.42 2.38  
              13.45 13.01 6.90 1.78  
PC .50 .10               .31  
  .34 .00               .04  
PCE 2.21 2.69 3.71 1.96 1.93 2.69 2.10 2.24 4.60 4.71  
  1.40 1.23 1.96 0.99 1.11 1.36 1.36 0.99 2.00 2.41  
PCF 11.86 17.49 18.53 26.45 35.32 52.95 57.30 65.00 65.00 68.38  
  4.35 5.99 8.54 10.98 17.19 23.57 29.18 23.73 24.02 23.37  
PGE           0.15 0.08        
PGM 10.10 12.91 12.98 10.50 11.09 10.33 10.51 9.91 11.20 13.12  
  6.42 7.25 8.02 6.32 6.93 7.27 7.70 5.92 6.37 6.42  
PNF             0.61        
WHEC                 0.78 0.28  
                  0.43 0.18  
WPB   1.15 2.41 5.05 11.27 15.31 1.37 0.46 14.87 24.10  
    0.47 1.22 2.59 6.45 9.45 1.16 0.13 7.63 10.20  


Table D-2

Average Number of USN/USCG Forces Assigned/
Average Number of USN/USCG Forces Employed
(By quarter)

  2/66 3/66 4/66 1/67 2/67 3/67 4/67 1/68 2/68 3/68 4/68
ADG   0.53                  
DD                     0.46
DER 6.65 6.75 4.92 5.13 3.33 2.00 2.24 2.30 2.41 2.07 1.14
  4.95 4.84 4.87 5.04 3.33 2.00 2.22 2.22 2.38 2.44 1.16
LSD 0.08                    
LST 0.25 0.99 1.00 1.01 1.00 1.00 1.00 1.00 1.00 1.00 0.86
  0.23 0.91 0.97 1.01 1.00 1.00 1.00 1.00 0.99 1.00 0.90
MCS         0.08            
MSC 2.24 3.33 2.97 2.61 0.82 1.08 0.92 0.69 1.14 1.61 1.14
  1.70 2.48 2.77 2.29 0.76 1.02 0.87 0.69 1.06 1.50 0.99
MSL                     0.23
MSO 7.68 6.01 5.29 4.90 5.13 5.25 4.05 4.23 3.62 3.32 3.65
  5.80 4.70 5.12 4.83 5.08 4.64 3.98 3.87 3.47 3.27 3.44
PB         0.54            
PBP         0.28            
PCE             0.00        
PCF 24.93 37.80 76.10 83.68 82.64 82.87 80.95 74.69 76.20 77.39 78.12
  21.12 33.91 34.47 35.11 43.60 41.24 33.44 34.59 35.74 34.84 26.62
PCG                   1.22  
PG         1.26 0.84 1.90 1.77 1.24 0.68 0.91
          0.42 0.50 1.10 1.15 0.72 0.87 0.42
PGM 0.08       0.23 0.05       0.08  
  0.01       0.07 0.05       0.05  
WHEC         1.52 3.00 2.71 2.86 2.58 2.78 2.66
          1.47 3.08 2.75 2.81 2.50 2.67 2.40
WPB 31.11 35.26 27.21 26.13 24.60 25.24 25.13 24.93 24.19 23.91 24.12
  15.69 16.20 14.92 16.23 15.26 14.68 14.61 13.74 14.24 14.26 13.64
WPC             0.72        
  1/69 2/69 3/69 4/69 1/70 2/70 3/70 4/70 1/71 2/71        
DD 0.37 0.00           0.15   0.15  
  0.34 0.03           0.08   0.06  
DER 1.26 1.15               0.08  
  1.22 0.90               0.08  
LST 1.00 1.00 1.09 1.00 0.84 0.93 1.00 0.82 1.00 0.75  
  0.97 0.91 1.09 0.99 0.84 0.96 1.00 0.92 0.98 0.76  
MSC 1.47 1.23 1.47 0.92 1.00 0.93 0.67        
  1.38 1.07 0.73 0.76 0.82 0.86 0.61        
MSO 3.53 3.85 2.47 1.33 2.00 1.84 2.08 1.59 2.47 2.02  
  3.18 3.25 1.74 1.18 1.67 1.63 1.85 1.02 1.56 1.37  
PB               0.11      
PBR       4.82 10.21 4.03          
        2.77 6.33 3.00          
PC 0.54                    
PCF 75.48 86.55 79.62 62.28 63.10 23.60 1.60 0.37      
  23.48 32.55 25.84 19.62 26.13 8.76 0.79 0.27      
PG 0.26 1.13 1.39 1.05 1.08 1.43 0.76 1.53 1.68 2.11  
  0.19 0.91 1.26 0.64 0.94 1.21 0.71 1.01 0.95 1.38  
PGH       1.35 0.11            
        0.60 0.06            
PGM   0.08 0.23 0.17 0.06 0.08 0.02 0.43 0.16    
    0.05 0.12 0.14 0.04 0.04 0.0? [illegible] 0.23 0.05    
WHEC 2.74 3.08 3.26 3.00 2.94 2.80 2.29 2.00 1.14 1.61  
  4.00 2.83 2.84 2.55 2.77 2.60 2.11 1.54 0.89 0.90  
WPB 24.78 22.45 24.37 16.74 13.28 6.53 0.38        
  13.94 17.74 13.45 10.42 4.95 2.10 0.28        
WPC   1.38                  
WPD             0.26        


Appendix E
Market Time Aircraft Force Levels

This appendix deals with Market Time aircraft force levels. Information available includes the number of VP and U.S. Navy and Army observation aircraft sorties for Market Time from April 1966 through June 1971 (figure E-1). An adequate estimate of the number of flight hours can be derived by multiplying the number of sorties by 12.

Sortie information for the second quarter of 1967 does not appear in the NASVA data base. It was collected separately from the OpRep-5s for the period, which lack sortie data for several weeks within the quarter.

The peak in VP sorties in the second quarter of 1968 probably resulted from increased surveillance because of the Tet offensive in February 1968 and another offensive in May. The drop in the number of sorties flown between the second quarter of 1968 and the first quarter of 1969 stems from the fact that, by 1969, P-3s were flying a single barrier covering all of SVN. Earlier, the same area had been covered by 2 to 3 aircraft, because P-5s and P-2s were also flying for Market Time; and they did not have the ability to stay airborne as long as the P-3s.

The number of VP aircraft committed to Market Time varied, but generally, this was the case:

1965-1967: Stationed at Sangley:

    Market Time/Yankee Station patrols (2 Yankee teams/day,
    Market Time take-off every 7 hours)
    1 P-3 squadron
    1 P-3 detachment from Naha
        9 P-3s/12 crews
    3 P-3s4 crews

Market Time:

    1 P-5 M squadron           12 P-5s/12 crews
    (Detachment at Cam Ranh Bay when seadrome operated)

    Stationed at Sangley with a detachment at Tan Son Nhut:

                   1 P-2 squadron

1968: Stationed at Sangley:

1 P-3 squadron with a detachment at U-Tapao of 3 P-3s/4 crews
1 P-3 squadron with a detachment at Cam Ranh Bay of 6 P-3s/9 crews.

Through 1971, 2 squadrons of 9 P-3s each were stationed at Sangley for Market Time. When an increased surveillance effort was needed, P-3s were drawn from Naha, Okinawa, and Iwakuni, Japan.


In January 1972, one VP squadron was deployed to CTG 72.3, augmented by a detachment of 3 P-3s/4 crews for the duration of the operation. The Market Time VP aircraft were all stationed at Cubi Point, Philippines, from then on.

During the height of the North Vietnamese offensive in the spring of 1972, as many as 20 VP sorties were flown daily over the South China Sea and Gulf of Thailand, with the majority of these flights dedicated to Market Time.

By September 1972, the situation had stabilized, and 4 P-3 flights were flown daily for Market Time, augmented by Ocean Surveillance Air Patrols.


Fig. E-1: Market Time VP and Observation Aircraft Sorties (by Quarters)


Appendix F
Group 125 Inventory and Trawler Characteristics

Table F-1 describes the characteristics of the trawlers in Group 125's inventory. There were 8 types of small logistic (SL) trawlers and a smaller craft called WU HU YF among Group 125 assets that might be used for infiltration to SVN.

Table F-2 gives 9 different versions of the Group 125 inventory covering 1970 through 1972.


Table F-1
Infiltration Trawler Characteristics

  SL-1 SL-2 SL-3 SL-4 SL-5
Length (feet) 125 125 88 99 110
Maximum beam (feet) 20 19 18 19 22
Displacement (loaded tons) 420 400 (est.) 280 280 300
Draft (feet) 10 11.3 8 8 9
Speed (knots) 12-15 17-20 12 14 (est.) 12
Cargo capacity (tons) 200 (est.) 100 (est.) 100 (est.) 95 (est.) 100-110
Crew complement 14 10-15 10-15 10-16 10-15
Armament Two 12.7mm. machine guns Three 14.5mm. mounts; or one 14.5mm. mount and two 12.7mm. machine guns (possible three 33mm. mounts) Three 12.7mm. machine guns Four 12.7mm. machine guns Three 12.7mm. machine guns (est.)
  SL-6 SL-7 SL-8 WU HU  
Length (feet) 96 125 150 81  
Maximum beam (feet) 18 19 27 18  
Displacement (loaded tons) 280 (est.) 400 (est.) 550 (est.) 150 (est.)  
Draft (feet) 8 (est.) 11.3 (est.) 12.8 (est.) Unknown  
Speed (knots) 15 (est.) 17-20 (est.) Unknown 10  
Cargo capacity (tons) 100 (est.) 200 (est.) 400 (est.) 20 (max.)  
Crew complement 10-15 10-15 Unknown Unknown  
Armament Two 12.7mm. machine guns, one probable 14.5mm. mount Two 12.7mm. machine guns and one 14.5mm. mount Two 12.7mm. machine guns (possible 23mm. or 37mm.) Two 12.7mm. machine guns  

Source: Vietnam Infiltration Trawler Identification Guide (intrigue); Supplement 1, Second Edition, Aug 1971, FIC Pac.


Table F-2
Inventory of Group 125a NVN Trawlers

  SL-1b SL-2 SL-3 SL-4 SL-5 SL-6 SL-7b SL-8 WU HUb
ComNavForV OpOrder No. 201-70   8 2-3 3-4 2 1 4    
NavForV N-2 Memo, 21 Nov 1970   6 3 3 1 1 4 8  
MACV 1970 Command History 33 6 2-4 3-5 1 1 4 8  
DIA--Defense Intelligence Digest, Apr 1971   6 2-3 3-4 1 1 4 10 7
FIC Pac--"Vietnam Infiltration Trawler Identification Guide," Aug 1971 32 6 2 3 1 0c 6 9 7
CIA ER-IM 7-156, Aug 1971 33 6 2 5 1 Unk 4 9 7
OEG Study 765, Mar 1972   7 3 3 1 1 5 9  
ComNavForV 1972, MT Review   6 2 2 1 1 6 9  
Prisoner Interrogation,d Oct 1972   2 4 5       5  

aThe assets of Group 125 considered here are those suspected of playing a role in enemy infiltration of SVN. Little reliable information on the assets of Group 125 appears to have been available before 1968. The most reliable information from CinCPac is that, in July 1966, Group 125 was reported to have 20 steel-hulled trawlers with a cargo-carrying capacity of 30 to 100 tons per ship.

bSL-1s, SL-7s, and WU HUs were not detected attempting infiltration, but the sources that list them consider these craft to have been potential infiltrators.

cOne SL-6 was found abandoned in March 1971.

dThe prisoners interrogated were members of the crew of the trawler sunk on 24 April 1972. None of the sources gave the same information, and the material presented is an interpolation of the two most complete sources.


Appendix G
Trawler Infiltration Attempts

This appendix lists detected steel-hulled trawler infiltration attempts by the day they were first detected, position at which they were detected, type of trawler involved, trawler destination, and the results of the mission.

All communist attempts to infiltrate SVN by steel-hulled trawlers were not thwarted by Market Time forces. At least two successes were confirmed, one each in 1970 and 1971. There are unsubstantiated reports of other trawler successes. A North Vietnamese captured in December 1973 who had served with Group 125 said that from 1963 to 1972, trawlers of Group 125 made 62 successful trips to SVN. If about 40 of these successful trips were made before Market Time, it implies at least 20 successful trips were made and not detected by Market Time forces.

In tables G-1 and G-2, the main source for position, date, and result was OEG Study 765; for destination, Intrigue.


(C) Table G-1
Detected Steel-Hulled Trawler Infiltration Attemptsa--First Era

  16 Feb 65 31 Dec 65 10 May 68b 20 Jun 66c 23 Dec 66 1 Jan 67 14 Mar 67
Position 12-52N/109-26E 07-49N/105-16E 08-54N/105-13E 08-38N/107-58E 14-28N/110-18E 08-38N/105-11E 15-27N/109-25E
Destination (SVN) Phu Yan (MR-2) An Xuyen (MR-4) An Xuyen (MR-4) Vinh Binh (MR-4) Binh Dinh (MR-2) An Xuyen (MR-4) Quang Ngai(MR-1)
Result Destroyed Aborted Destroyed Captured (partially destroyed) Aborted Destroyed Destroyed
Type Unknown SL-5 SL-5 SL-4 SL-4 Unknown SL-4
  11 Jul 67 22 Feb 68d 28 Feb 68e 29 Feb 68f 29 Feb 68g 29 Feb 68h  
Position 15-23N/109-38E 15-10N/112-19E 09-54N/109-29E 14-24N/111-27E 15-20N/110-43E 12-17N/110-30E  
Destination (SVN) Quang Ngai (MR-1) Binh Dinh (est.) MR-2 An Xuyen (MR-4) Binh Dinh (est.) MR-2 Quang Ngai (MR-1) Khanh Hoa (MR-2)  
Result Captured (partially destroyed) Aborted Destroyed Destroyed Aborted Destroyed  
Type SL-4 SL-4 SL-5 SL-3 SL-4 SL-2  

aMarket Time air detected most of these attempts, but other means of detection were also used.

bPosition seems to be highly improbable; it would place the trawler on dry land in the Ca Mau Peninsula.

cOEG Study 765 cites northern SVN as the destination. Intrigue cites trawler type as SL-4.

dIntrigue cites trawler type as SL-5, N-2 Memo of 21 Nov 1970 cites Quang Ngai (MR-1) as destination.

eOEG Study 765 cites northern SVN as the destination Intrigue cites trawler type as SL-4.

fIntrigue cites trawler type as SL-4 and result as aborted.

gIntrigue cites trawler type as SL-3 and result as destroyed.

hOEG Study 865 cites southern SVN as the destination.


(C) Table G-2
Detected Steel-Hulled Trawler Infiltration Attempts--Second Era

24 Aug 69a 16 Nov 69 23 Dec 69 11 May 70 21 Apr 70 19 May 70 29 May 70b 10 Jun 70 6 Jul 70 2 Aug 70c 28 Aug 70 4 Sep 70 9 Oct 70c
Position 09-25N/103-30E 07-24N/105-08E 10-54N/112-13E 07-15N/105-25E 05-51N/109-00E 12-00N/114-07E 18-27N/106-10E 08-15N/105-40E 07-31N/109-45E 18-01N/113-23E 11-24N/112-37E 07-48N/109-34E 18-13N/112-32E
Destination An Xuyen (MR-4) An Xuyen (MR-4) An Xuyen (MR-4) An Xuyen (MR-4) An Xuyen (MR-4) An Xuyen (MR-4) Unknown An Xuyen (MR-4) An Xuyen (MR-4) Unknown An Xuyen (MR-4) An Xuyen (MR-4) Unknown
Result Aborted Aborted Aborted Aborted Aborted Aborted Aborted Aborted Aborted Aborted Probable success Aborted Aborted
Type SL-6 SL-4 SL-6 SL-4 SL-4 SL-4 SL-3 SL-4 SL-4 SL-4 SL-4 SL-6 SL-3

28 Oct 70d 17 Nov 703 24 Feb 71 22 Mar 71 27 Mar 71 30 Mar 71 8 Apr 71 3 Oct 71f 17 Oct 71 28 Oct 71 16 Dec 71 19 Dec 71 28 Dec 71
Position 12-00N/173-41E 08-46N/107-30E 11-27N/111-39E 16-16N/115-17E 08-42N/110-44E 08-37N/105-06E 09-44N/111-27E 16-35N/112-51E 13-24N/113-13E 9-38N/112-06E 4-51N/107-41E 4-45N/108-18E 5-18N/110-25E
Destination An Xuyen (MR-4) Kien Hoa (MR-4) An Xuyen (MR-4) An Xuyen (MR-4) An Xuyen (MR-4) An Xuyen (MR-4) An Xuyen (MR-4)
Result Aborted Destroyed Aborted Aborted Aborted Success Destroyed Aborted Aborted Aborted Lost contact Aborted Aborted
Type SL-4 SL-3 SL-8 SL-8 SL-4 SL-6 SL-8 SL-3 SL-4 SL-6 SL-8 SL-4 SL-4

16 Jan 72 2 Feb 72 17 Feb 72 27 Feb 72 15 Mar 72 22 Mar 72 25 Mar 72 28 Mar 72 Apr 72g Apr 72g 22 Apr 72 24 Apr 72h
Position 9-52N/111-06E 4-42N/105-57E 8-38N/113-17E 9-49N/117-28E 8-06N/115-43E 11-09N/111-07E 9-51N/117-17E 13-52N/112-46E Not available Not available 14-04N/112-12E
Result Aborted Aborted Aborted Aborted Aborted Aborted Aborted Aborted Aborted Aborted Aborted Destroyed
Type SL-6 SL-4 SL-3 SL-8 SL-6 SL-4 SL-8 SL-6 NA NA SL-3 SL-4

aIntrigue cites position the trawler was first detected at as 16-02N/113-05E, far north of 09-25N, 103-30E.

bIntrigue cites position the trawler was first detected at as 19-02N/112-14E; OEG Study 765 cites destination as southern SVN.

cOEG Study 765 cites destination as southern SVN.

dIntrigue cites position the trawler was first detected at as 12-00N/113-41E; 173-41E was probably an error in OEG Study 765.

eN-2 Memo of 21 Nov 1970 cites destination as An Xuyen.

fSuspected destinations are not given for the remaining trawlers detected attempting infiltration, although it is probable they were all heading for MR-4.

gThere were 2 trawler infiltration attempts detected in Apr 1972 in addition to those of 22 and 24 Apr. The only available information is that they aborted their missions.

hWas detected 13 Apr while exiting Hainan Strait.

Source for Oct 1971 through Mar 1972, ComNavForV "Market Time Review 1972".

Source for Apr 1972, message traffic.


Appendix H
Suspected Merchant Ship Smuggling on Mekong River

(U) There are many theories of how NVN resupplied VC/NVA forces in SVN (especially in MR-4) via ways other than the Ho Chi Minh trail. Some of these theories have been generally accepted after much debate within the intelligence community.

(C) It seems certain now that the communists were shipping arms and munitions through Sihanoukville between 1966 and 1969, and that Cambodia was probably used during the early 1960s as part of the resupply network. Cambodian complicity was not officially acknowledged by many U.S. policy makers until after Sihanoukville was closed to the communists.

(U) Seaborne infiltration has been accepted, at least since 1967, as an important resupply route. It is possible that supplies were smuggled aboard merchant ships using the Mekong River. This idea was proposed to account for weapons and munitions acquired by the VC in southern SVN; those supplies simply could not be explained away by seaborne infiltration or shipments through Cambodia. The theory is still disputed, but, as a form of seaborne infiltration, it should be considered.

(C) About 30 free-world merchant ships sailed up the Mekong from Cape St. Jacques to Phnom Penh each month. Early in the war, arms and munitions were reported by intelligence to have been smuggled on some of these merchant ships. At the time of the cease-fire in January 1973, there was enough circumstantial evidence to strongly suggest that such smuggling was continuing even then. Many merchant ships steaming between Singapore or Hong Kong and Phnom Penh used flags of convenience, that is, the ships were owned by a company of one nationality and registered with another nation.

(U) Beginning in 1968, all merchant ships traveling on the Mekong had to be escorted. The convoys were formed at Vung Tau and ended at Tan Chau (near the Cambodian border). Any ship flying a communist flag, claiming a communist port as its last port of call, or carrying military goods was not allowed to sail up the Mekong.

(C) The convoys were generally very lax, as were the South Vietnamese customs inspections at Vung Tau. In addition, complicity of South Vietnamese and Cambodian officials in these cursory inspections is strongly suspected. Cleverly concealed secret compartments were discovered on several of the ships suspected of smuggling, and smuggling of commercial goods has been proven conclusively.

(U) Most of the merchant ships traversing the Mekong were not seaworthy; nor were their goods insured. Therefore, the cargo had to be lucrative to entice them to make the trip from Singapore or Hong Kong to Phnom Penh. The bills of lading listed expensive consumer goods as cargo (such as porcelain dishes, apples, and pears) rather than staples that a country as poor as Cambodia might be expected to import.

(C) This unusual cargo generally filled less than the full cargo capacity of the ship. It would not have been profitable to the owner to send an unseaworthy, underloaded ship on


such a long trip unless it carried some kind of other profitable cargo, such as war supplies. The secret compartments discovered on some of the merchant ships suspected of smuggling arms and munitions could easily hold as much war material as any of the 100-ton Group 125 trawlers. The secret compartments on these rotting hulks must have been very expensive to construct.

(C) The scenario offered by the main proponent of this theory - Frances L. Brady of NOSIC - is that the mercenaries who owned the merchant ships are suspected of having done most of their business for the communists, although they probably sometimes carried totally legitimate cargo when there was nothing to be smuggled.

(C) Materials to be smuggled - whether consumer or war goods - were loaded on a ship together with a legally consigned cargo for Phnom Penh. The merchant ships could load contraband left by Soviet or Chinese ships in Hong Kong or Singapore (or both) for transshipment. As the ships were convoyed up the Mekong, they might take advantage of a lax escort and offload while still in SVN, or they could offload across the border in Cambodia. Another possibility was that the cargo was taken to a warehouse in Phnom Penh by a communist and distributed from there.


Companies and Individual Suspected of Smuggling Activities

(C) The An Kan Shipping Company of Hong Kong is owned by Kuch An Aka Kuo Wen Ch'uan; subsidiary companies include:


    Nam Hoa Import/Export Shipping Company
    Route Transport Trucking Company
    Armatuer and Industrial Company (reportedly secret owner)
    Data Transitaire


    An Kan Shipping Company, Ltd.
    Southern Shipping Company


    Nam Fong Shipping Company, Ltd.


    Nam On Navigation Company


    Fortuna Navigation Company


    An Kan Shipping Office

The Gwan-Gwan Shipping Company of Singapore.

Ocean Tramping Company is Chinese owned and charters all of its ships to Communist China.

Denis Freres Company of Saigon. This company was reported in March 1970 to be transferring assets to Pacifico in Saigon.

Pacifico has a subsidiary office in Phnom Penh and also has under its auspices the Pan American Ticket Agency located at 4 Tu Do Street in Saigon.


Long Van Tu--owner of Builders and Suppliers in Saigon.

Winkler Lloyd Pte, Ltd. Shipping Company located in Singapore; there is a Saigon representative located at No. 10 Duy Tan.

Tran Quy Chan--owner and president of United Contractors (UNICO) in Saigon.

American Pacific Corp. Pte., Ltd., in Singapore.

British Asian Pte., Ltd., in Singapore.

The merchant ships Virginia, Monica, Felicity, Eternity, Prosperity, Sincere Orient, Wan Khim, Yung Tung, Forsees, Yellow Dragon and Silver Dragon (Aka Tonle Sap), among others, are suspected to have been involved in commercial smuggling and may also have been involved in support of the NVA/VC.


Appendix I
Rules of Engagement

This section of the Market Time Rules of Engagement has been reproduced from the 1970 Coastal Surveillance Force Operation Order.


  Naval Forces, Vietnam
Task Force 115
Coastal Surveillance Force
Cam Ranh Bay, Vietnam
DTG: 202335Z SEP 70 Message Ref: CR0/01

Operation Order


Reference: (a) CTG 72.3 OPORD 201-(YR)

1. The following Rules of Engagement are effective for Task Force 115.


a. SEASIA. For purposes of these rules, SEASIA includes the air space, land mass and territorial/internal waters of:

1. Thailand, Laos, Cambodia, North and South Vietnam.
2. The international waters and air space of:

a. The Gulfs of Thailand and Tonkin.
b. The South China Sea in or over which U.S. forces operate in relation to U.S. Objectives in SEASIA.

b. MARKET TIME Operations. The conduct of counter sea infiltration operations in SEASIA by U.S. forces in coordination with RVN forces to prevent sea support of the Viet Cong insurgency in RVN.

c. Territorial Seas. A belt of sea adjacent to a coastal state three miles in breadth measured from the low water mark along the coast. However, in those states claiming territorial seas of more than three miles, that distance shall be observed for these rules as if it were the width of their territorial seas.


Operation Order

    (1)       Thailand       6 miles presumed       (the "presumed" claim is to be observed as valid width)
    (2)       Cambodia       5 miles
    (3)       South Vietnam       3 miles
    (4)       North Vietnam       12 miles presumed
    (5)       Communist China       12 miles

    d. Inland Waters. Waters to landward of the territorial seas.

    e. Contiguous Zone. A zone of the high seas, contiguous to the territorial area of the RVN and extending to a maximum of 1 miles from the base line from which the territorial sea is measured.

    f. Defensive Sea Areas (DSA). The territorial seas of RVN have been declared a Defensive Sea Area by the Government of Vietnam. Ships (less warships) of any country operating within the territorial sea are subject to visit and search if not clearly engaged in innocent passage.

    1. In the territorial sea of the RVN, for the purpose of TF 115 operations, the Brevie Line delineates the islands belonging to RVN and Cambodia. The Brevie Line was established as an administrative boundary to assign responsibility of the islands to pre-World War II French authorities in Indo China. It runs 234° (true) from the intersection of the Cambodian border with the Gulf of Thailand coast north of Ha Tien, to a point three kilometers off Phu Quoc Island, thence circumscribes Phu Quoc to the north and west at a distance of three kilometers before rejoining the original bearing of 234° (true) southeast of the island. This line is depicted on Army Map Service Sheets 5471-I, 5741-II, 5842-III, 5841-IV, all series L-701; and upon breadth of territorial waters. Since Cambodia claims a 5 miles territorial sea, 65 miles shall be observed for these rules as applied to Cambodia and her islands. MARKET TIME forces are free to operate outside the territorial waters of Cambodia and her islands.



Operation Order

2. To standardize the interpretation of the above, the following points (Chart H. O. 3146), when connected by straight lines, outline the boundary of the RVN defensive sea area in the vicinity of the Cambodian/RVN border.

a. The Cambodian/RVN boundary at 10-25-12N, 104-26-28E.
b. 10-16-39N, 104-14-23E
c. 10-17-30N, 104-13-30E
d. 10-21-05N, 104-11-15E
e. Thence along the median line between the base lines from which the territorial seas are measured to 10-21-36N, 103-43-50E.

g. Immediate Pursuit. Pursuit initiated in response to actions or attack by hostile aircraft or vessels as defined in these rules of engagement. The pursuit must be continuous and uninterrupted and may be extended as necessary and feasible over territorial and international air space and seas as prescribed herein. Sometime known as "Hot Pursuit".

h. Friendly Forces. All South Vietnamese (RVN), Royal Thai (RTG) and Royal Laotian (RLG) air, ground, and naval units and all other non-U.S. ground, and naval units operating with the RVN, RTG, RLG and including such quasi-official organizations as "Air-America" and "Bird and Sons". Although Cambodian troops have been operating in conjunction with the RVN forces, U.S. forces will not enter Cambodian territory or board Cambodian Navy ships except in specific cases approved by COMUSMACV.

I. Hostile Fire Incidents. Units of TF 115 are authorized to return fire upon being fired upon and to fire in support of friendly units receiving hostile fire. Commanding officers receiving requests for gunfire support under conditions where no U.S. spotters are available shall respond only under the gravest of circumstances, such as when they are under hostile fire, or friendly forces are positively known to be under hostile fire, and gunfire



Operation Order

support can be effected with positive assurance that the friendly forces and/or non-combatants will to be harmed. The threat of impending action is not generally sufficient to fire without U.S. spotter personnel to observe the fall of shot. Commanding officers are expected to display sound judgement in replying to fire form the vicinity of populated areas. An immediate report of incidents involving the return of hostile fire will be made to CTF 115 and the appropriate CSC. CSC's will ensure that the cognizant province chief is kept informed. All NGFS will be in accordance with Annex K of the OPORD.

j. Hostile Aircraft. The definitions below apply to aircraft in the air space of RVN and Thailand or over SEASIA international waters.
An aircraft which is visually identified or is designated by the U.S. Director of Air Operations Center, or his authorized representative, as a Communist Bloc aircraft operation in RVN/Thailand territorial air space without proper clearance from the government concerned; or

1. An aircraft which is observed in one of the following acts:

a. Attacking or acting in a manner which [are] indicated with reasonable certainty an intent to attack U.S./friendly forces or installations.
b. Laying mines, without the permission of the government concerned, within friendly territorial seas or inland waters.
c. Releasing free drops, parachutes, or gliders over friendly sovereign territory without permission of the government concerned and obviously not in distress. The foregoing includes the unauthorized landing of troops or material in friendly territory.

k. Hostile Vessel. (Surface or sub-surface) A vessel in RVN or Thailand inland waters and territorial seas or SEASIA international waters which is engaged in one of the following acts:



Operation Order

1. Attacking or acting in a manner which indicates within reasonable certainty an intent to attack US./friendly forces or installations, including the unauthorized landing of troops or material on friendly territory.
2. Laying mines within friendly territorial seas or inland waters without permission of the government concerned.
3. Engaged in direct support of attacks against RVN or Thailand.

l. Hostile Ground Forces. Those ground forces which attack U.S. or friendly forces or installations.

m. Visit. Boarding a non-U.S. vessel and examining the ships, papers and documents.

n. Search. Inspecting a vessel and its cargo.

3. Decree on Sea Surveillance. The Government of the Republic of Vietnam in April 1965 issued the following decree on Measures of Sea Surveillance:

"Due to the fact of a constant and increasing infiltration by sea into the Republic of Vietnam of Viet Cong personnel, arms, ammunition and various war supplies, the Prime Minister has signed decree number 81/NG of the 27th of April 1965, by which the following defense measures have been decided upon to ensure the security and the defense of the territorial waters of Vietnam:

I. The territorial waters up to the three mile limit is declared a Defensive Sea Area. The passage of vessels through the territorial sea of the Republic of Vietnam which is prejudicial to the peace, good order or security of the Republic of Vietnam is not considered as innocent passage and is forbidden by the law of the Republic of Vietnam. Ships of any country operating within the territorial sea of the Republic of Vietnam which are not clearly engaged in innocent passage are subject to visit and search, and may be subject to arrest and disposition, as provided by the law of the Republic of Vietnam in conformity with accepted principles of international law.



Operation Order

Cargoes will be considered suspect unless it can be clearly established that they are destined for a port outside the Republic of Vietnam or a legitimate recipient in the Republic of Vietnam. Cargoes will be considered particularly suspect if containing any of the items listed below:

  1. Weapons, ammunition, electrical and communications equipment.

  2. Primer, mine, gunpowder and other explosives.

  3. Chemical products which can serve military purposes (such as ammonia nitrate, sodium nitrate, potassium nitrate, calcium nitrate, potassium chlorate, ammonia chlorate, potassium perchlorate, potash perchlorate, soda perchlorate, sodium percholorate, disphenylamine, contialite, ether, nitro cellulose, nitro glycerin, magnesium, aluminum powder, barium chloride, mercury fulminate, benzene, chlorine, calcium carbide, acetylene, liquid and compressed oxygen, sulphur, acetone, nitric acid, sulfuric acid, hydrochloric acid).

  4. Medical supplies of Communist North Vietnam, Communist China or Soviet Bloc origin.

  5. Foodstuffs of Communist North Vietnam, Communist China or Soviet Bloc origin.

II. The passage of vessels through the water contiguous to the territorial sea of the Republic of Vietnam up to twelve nautical miles from the baseline from which the breadth of the territorial sea is measured are subject to the control of the Republic of Vietnam to the extent necessary to prevent or punish infringements of the customs, fiscal, immigration and sanitary regulations effective within the territory or territorial sea of the Republic of Vietnam. Entry of materials and merchandises to the Republic of Vietnam other than through recognized routes or ports of entry is forbidden by customs regulations of the Republic of Vietnam.

Entry into the Republic of Vietnam of persons other than through recognized routes or ports of entry is forbidden by immigration regulations of the Republic of Vietnam. The Government of the



Operation Order

Republic of Vietnam intends to enforce strictly these customs, fiscal or immigration regulations.

Accordingly, vessels within the contiguous zone suspected of preparing to aid in infringements of the customs, fiscal or immigration regulations of the Republic of Vietnam are subject to visit and search, and may be subject to arrest and disposition, as provided by the law of the Republic of Vietnam in conformity with accepted principles of international law.

III. It is the intention of the Republic of Vietnam to act beyond the 12 mile contiguous zone to prevent or punish any infringement of the laws of the Republic of Vietnam by vessels flying the flag of the Republic of Vietnam or reasonably believed to be South Vietnamese, though flying a foreign flag or refusing to show a flag; the action taken against such ships may include stopping, visiting, and searching. If the reasonable suspicions as to Vietnamese nationality prove unfounded and the vessel has not committee any act justifying these suspicions, the vessel will be permitted to continue and reasonable compensation paid by the Government of Vietnam for any damage which may have been sustained.

IV. Vessels which are within the territory, the territorial sea or the contiguous zone of the Republic of Vietnam and which are suspected of infringing the above regulations within the territory or territorial sea of the Republic of Vietnam are subject to hot pursuit on the high seas as provided for in international law.

V. The Government of the Republic of Vietnam has requested an[d] obtained the assistance of the Government of the U.S.A. for the full cooperation of the U.S. Navy with the naval forces of the Republic of Vietnam to enforce the new security and defense measures as ordered by the Prime Minister of the Republic of Vietnam.

SAIGON, 27 April 1965."

4. Rules of Engagement

  1. U.S. forces operating in support of MARKET TIME operations are authorized:



Operation Order


    1. Within the RVN Defensive Sea Area (territorial waters) to stop, visit, and search vessels (less warships) of any nation not clearly engaged in innocent passage.

    2. Within the contiguous zone of the RVN to demand the identification and a declaration of intent of vessels (less warships) of any nation. Vessels flying the RVN flag which give a manifestly false response to these demands, or give other valid grounds for suspicion that all or part of the cargo or personnel is intended to be or has been taken directly into the RVN in violation of the customs, fiscal, immigration, or sanitary laws of the RVN may be stopped, visited and searched. (The Blue Book of Coastal Vessels South Vietnam 1968 contains a resume of these laws. See Annex H.) All Chinese Nationalist trawlers or small craft which are encountered within the 12 mile limits of the South Vietnam coat will be stopped, visited and searched. Other merchant shipping of foreign flags, except RVN, will not be visited and searched unless specifically authorized by CTF 115. TF 115 units will report to CTF 115 by rapid means a description of actions of vessels providing a basis for suspicion of violation of innocent passage status. Communist Bloc merchant shipping will not be requested to stop unless so directed by CTF 115. When doubt exists about the innocent passage of Communist Bloc ships, TF 115 units will report reasons for suspicion by an immediate precedence message to CTF 115, and will meanwhile trail the Communist Bloc ship. Units will ensure that their actions and maneuvers cannot be construed as harrassing merchant shipping. In this regard a properly annotated DRT or similar plot will be maintained when within 6000 yards of merchant shipping.

    3. In international waters beyond the contiguous zone, to stop, visit and search all vessels flying the flag of the RVN or reasonably believed to be South Vietnamese, though flying another flag or refusing to show flag, in order to prevent any infringement of the laws of the RVN. When identity has been determined to be other than RVN, the vessel shall be authorized to proceed.

    4. The limits within which customs, immigration, fiscal and sanitary regulations of the RVN may be enforced in the vicinity of the Cambodian/RVN border are defined in paragraph 2.f.(2) above.



Operation Order

b. U.S. forces are authorized to detain the following vessels which have been intercepted pursuant to the above, until custody is assumed by RVN forces.

1. Vessels determined to have violated or to be preparing to violate laws and regulations of the RVN.
2. A vessel which refuses to permit visit, or having been visited, refuses to permit search.
3. An intercepted vessel within the contiguous zone which fails to proceed as previously stated or directed.

c. A vessel not subject to detention shall be permitted to proceed to its stated port of destination.

d. Procedures for visit and search will be in accordance with the guidance of Annex I. Reports of visit and search will be made in accordance with Annex C.

e. The minimum force necessary to accomplish surveillance operations will be exercised, up to and including destruction if required.

1. Violators of curfew and prohibited zones (who may or may not be subjected to gunfire by VNN forces) will not be fired upon by TF 115 units unless the violator qualifies as a HOSTILE VESSEL in accordance with paragraph 2.k. of this Annex or attempts to evade and ignores warnings to stop as described in TAB C to Appendix I to Annex B.
2. Every peaceful method at hand should be first exhausted when attempting to stop a junk for boarding and search. This failing, warning shots would be the next step. If it is obvious the junk is deliberately trying to evade, direct fire may be used as a last resort. Firing should cease if the junk appears to be stopping.
3. It is permissible to continue DIRECT FIRE against an evading junk that beaches and against its fleeing occupants provided the location is not in the vicinity of a hamlet or village. Any fire in vicinity of hamlets or villages must be conducted strictly in accordance with Annex K.

f. Commanders will recognize the responsibility of language difficulties, and allow sufficient time for the ship's master to fully realize the consequences for failure to respond properly.



Operation Order

g. U.S. forces in SEASIA are authorized to attack and destroy any hostile ground forces as herein defined which attack U.S. forces or friendly forces in RVN.

h. Immediate pursuit may be conducted as necessary and feasible pursuant to the above, subject to the following conditions and limitations:

1. In the event U.S. forces are attacked by hostile forces in South Vietnam, Thailand, North Vietnam or SEASIA international waters/air space, U.S. forces may conduct immediate pursuit over international waters or into territorial seas or air space of North Vietnam and Laos; and of Cambodia when actually engaged in combat, combat for these purposes being characterized by actual exchange of fire.
2. No pursuit is authorized into the territorial seas or air space of Communist China.
3. U.S. forces which, under the limitations of these rules, enter unfriendly territorial land, sea, or air spaces in immediate pursuit are not authorized to attack other unfriendly forces or installations encountered unless attacked first by them, and then only to the extent necessary for self defense.
4. Units challenging a suspicious contact, should avoid approaching the contact so close and in such a direction as to place themselves in a position to be rammed or run down. Approaching the contact from either quarter is generally the most advantageous and defensible position.

i. Patrol aircraft limitations and CPA will be in accordance with reference (a) and current SEVENTHFLT operating instructions.


I - Operational guidance for surveillance of possible infiltrator trawlers outside the RVN contiguous zone.



  Naval Forces Vietnam
Task Force 115
Coastal Surveillance Force
Cam Ranh Bay Vietnam
DTG: 202335Z SEP 70
Message Ref: CRO/01

Operation Order

Appendix I to Annex Dbr>Operational Guidance for Surveillance of Possible
Infiltrator Trawlers Outside the RVN Contiguous Zone

1. Upon detection of a suspected infiltration trawler, aerial photography should be obtained as soon as possible. FICPACFAC will process and classify contact, and will notify CINCPAC and other concerned commands. If the analysis identifies the trawler as an NVN infiltration type trawler, and other information available tends to confirm this identification, then the contact will be further prosecuted. Undetected or overt surveillance will then be directed depending on factors such as:

a. Location of trawler.
b. Trawler's anticipated movements.
c. Availability and location of friendly forces.

2. COMSEVENTHFLT in conjunction with COMNAVFORV will make a determination as to the air, surface, or submarine forces to be used to conduct surveillance.

3. If overt detection is directed, it is expected that it will be conducted by one or more surface ships. The surface ships will proceed to intercept the suspected vessel. After interception the vessel will be approached and hailed. An attempt will be made to establish its identity by:

a. International signals.
b. Ordering the vessel to hoist its national flag.
c. Interrogation with bull horn.
d. Other recognized means.

If possible, determine the intent (CARGO, DESTINATION) of the vessel.

4. If the vessel complies, and there are no reasonable grounds for suspecting a threat, the vessel will be allowed to proceed. In this case surveillance



Operation Order

should be continued to confirm the validity of the information. If further surveillance indicates that the information is not valid, then the vessel becomes increasingly under suspicion, and this additional information therefore supports a determination that the vessel is a threat. If the vessel refuses to respond, but takes no threatening action, surveillance will continue until terminated by higher authority.

5. Should the vessel, at any time, act in a hostile manner which indicates within a reasonable certainty, an intent to attack U.S. forces, then U.S. forces will take necessary action to defend themselves. Any lesser action will be reported to CINCPAC info COMUSMACV and COMNAVFORV in accordance with reporting procedures. (Appendix V, Annex C).

6. If undetected surveillance is maintained, no direct action will be taken against the vessel until such time as it is determined by CINCPAC to constitute a threat. CINCPAC will determine if the contact is hostile based on information provided by the surveillance ship. Surveillance ships must be familiar with the thirteen indicators supporting hostility determination. These thirteen indicators are:

a. Vessel was on a course which could permit entry into the waters of the Republic of Vietnam within the twelve mile limit, and after detection, altered course radically.
b. Vessel apparently has topside cargo and/or armament which may be covered by tarpaulins or nets.
c. Vessel is in a position to arrive in RVN waters within the twelve mile limit during hours of darkness.
d. Vessel is in a position to arrive near the RVN coast during a period of high tide.
e. Lunar period is one of no moon or in the first or last quarter.
f. Vessel is in a position to arrive in RVN waters within the twelve mile limit during holiday periods or periods of truce.
g. Vessel flies a North Vietnamese flag or displays no flag or other form of national identity.
h. Vessel is showing no lights at night.
i. Vessel appears to be headed toward an area of enemy troop concentration or enemy control.



Operation Order

j. Vessel is riding low in the water, indicating it to be fully loaded.
k. The overall track of the infiltrator is similar to the pattern established by previous infiltration trawlers.
l. Detection of more than one vessel apparently engaged in a coordinated infiltration attempt.
m. Other all-source intelligence information.

Surveillance ships will use these indicators as guidance for submission of SITREPS. These indicators are not to be considered all-inclusive, nor are they to be used as a check-off list, and not all necessarily need to be satisfied to determine hostility. Therefore, Commanding Officers must ensure that all other pertinent information is made available to higher authority.

7. If, at any time, the vessel's actions or movements are such as to constitute a threat, i.e. acts in a manner which indicates with reasonable certainty an intent to land troops or material on friendly territory (RVN) in support of VN/NVA activity, or such as to provide additional evidence to support such a conclusion, it will be reported to CINCPAC info COMUSMACV and COMNAVFORV in accordance with reporting procedures (Appendix V to Annex C). Based on all information available, CINCPAC may then declare the vessel hostile and direct that visit and search procedures be initiated. At the time such action is actually initiated by the on-scene commander, the vessel must still constitute a threat. Due to the short time in which a declared hostile vessel could change its nature, i.e. abandon its mission, the on-scene commander will make a final assessment of hostile intent before executing visit and search procedures. For example, an identified NVN infiltration type trawler under surveillance is on course parallel to the RVN coast, and in a location which would permit arrival in RVN waters within the twelve mile limit during hours of darkness. He sets a course toward the coast, thereby demonstrating an imminent intent to land materials on the beach. CINCPAC declares the vessel hostile and directs visit and search. However, the vessel abandons its mission by turning away from the coast prior to initiation of visit and search procedures. The vessel should then no longer be considered hostile by the on-scene commander, and visit and search will be cancelled. CINCPAC would be immediately appraised of these new developments.

8. While a declaration of hostile, under the ROE permits destruction, in order to preclude the possibility of an irreversible error, CINCPAC requires that initiation of visit and search procedures will precede any destructive fire action, provided the vessel is not posing a direct threat to U.S. forces.



Operation Order

Only the minimum forces necessary to accomplish the mission will be applied to any stage in the process.

9. Once the intent to initiate visit and search procedures has been conveyed to the vessel, the action will then be continued even though the hostile vessel changes course and/or speed. Further, once the visit and search procedures are initiated, the action will be continued to a completion which could be from acceptable identification to destruction. However, if, prior to the conveyance of the intention to initiate visit and search procedures, a vessel demonstrates its intent, not simply to escape for the moment, but to abandon what might have been classified as a hostile act, then the threat has been effectively neutralized. The necessity for a classification of hostile followed by varying levels of overt actions then would no longer exist.



Appendix J
Major Findings From Responses to Market Time Questionnaire

Responses were solicited from key Market Time participants by a questionnaire prepared by the author (page J-2). Sixty of the responses proved to be very helpful; these took the form of written answers, interviews, or both. Copies of the responses to the questionnaire may be requested form the management Information Office, Center for Naval Analyses, 1401 Wilson Blvd., Arlington, Va. 22209.

The responses to the questionnaire and personal papers supplied by some of those solicited have been used in preparing this paper. The major findings resulting from the responses to the questionnaire are:

  • There was inadequate coordination between the intelligence community and the operators. If adequate intelligence was actually available, not enough timely information was passed to the operators. It is not clear whether the problem was caused by the lack of interest or education on the part of operators concerning the importance of intelligence, or whether an unsatisfactory effort was made by the intelligence community to disseminate the information. Until 1968, not even CTF 115 was cleared to receive special intelligence (SI) information. There were valuable sources that were not exploited as bases of operations. In addition, the operators generally had an inadequate appreciation for the importance of operations security, particularly communications security.

  • Accompanying the turnover problems created by a short tour was the insensitivity shown towards the Vietnamese. There was, until late in the war, inadequate indoctrination into the language and culture of SVN. This inadequate appreciation of the Vietnamese people hampered the crews on Market Time patrols.

  • Too much emphasis was placed (apparently by Washington) on detection/inspection/boarding statistics of Market Time forces. No adequate measure of effectiveness was developed to judge the performance of inner- and outer-barrier crews since contraband was seldom discovered. Since the detection/inspection/boarding statistics were used to determine whether the ships or boat divisions were doing their jobs, many of the statistics were inflated. Unfortunately, the statistics meant very little, considering the time expended in collecting them. The fact that contraband was not discovered did not imply Market Time was not an effective deterrent to infiltration or transshipment. If Market Time forced the enemy to jettison contraband before submitting to search, the operation was doing its job, and no one would know except the enemy crew that had lost its cargo. Also, the statistics revealed nothing about the thoroughness of the search. There was no way to know the effect it had on the enemy, or his ability to continue his efforts.



  1. What are your comments on:

      Personnel (level of and quality)

      Tour length

      Morale (and how it related to the aggressiveness of patrols, especially by the Vietnamese)


      Coordination of forces

      Operational reporting

  2. What were the most important problems you encountered? How were they attacked?

  3. What innovations were developed on your watch? How were they identified?

  4. What intelligence on enemy infiltration potential and activity was available? Was it adequate for your needs? How was intelligence used?

  5. Do you think the scope and intensity of the Market Time effort were commensurate with the threat?

  6. If circumstances should warrant another MT attempt, in what general ways would your recommended approach and concepts of operations differ from past experience?

  7. Do you have any personal files or notes on MT which could contribute to our study effort?

  8. What aspects of MT do you think it would be most profitable to study?

  9. What do you think are the major lessons learned from the MT operation?

  10. Are there any MT participants in addition to those on the distribution list to whom you think it would be worthwhile to address this questionnaire?



Published: Mon Nov 23 09:02:18 EST 2020