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MAC-V-SOG Command History Annex B:
(1971-1972) Volume I,
The Last Secret of the Vietnam War
by Charles F. Reske
[Webmaster note: This web page includes excerpts from the second
book in a series of three.]
3. Maritime Studies Group, MACSO-37 (Appendix 11). The Maritime Studies
Group was responsible for covert maritime operations conducted by the
Vietnamese Coastal Security Service (CSS). The capability to carry out
missions against North Vietnam was maintained through extensive training
at Da Nang and by conducting operational missions against selected targets
in South Vietnam. ---SENTENCE DELETED-- CSS had progressed to such a point
by July 71 that they assumed all responsibility from the US for planning
and carrying out missions. ---SECTI0N DELETED --
Nightly training patrols with the PTF's were conducted from Da Nang
north to the DMZ and south to Cu Lao Re Island, located to the east of Chu
Lai. The PTP's departed Da Nang at 18:00 H on a twelve hour patrol.
Training emphasized navigation and tactics. Suspected enemy craft were
stopped and searched, if within the twelve mile limit. This training
program started on 15 Dec 70 and is intended to continue indefinitely.
A mission using four PTF's in the Hon Nieu Island area was run on 19
and 20 Feb. Three large targets were observed west southwest of Hon Nieu
One was a 380 foot freighter in the Hung Chi 151, 152, or 153 class. It
had a yellow star and stripe on its stack and was determined to be of
Chinese registry. The presence of this type of ship at this location was
confirmed by aerial photography on 16 Feb.
The other two targets were a 300 foot tanker and a 200 foot freighter.
While photographing these vessels, an enemy 60 foot patrol craft
approached from the south and fired 12.7mm guns at the PTF's. The enemy
craft was engaged and strafed by 40mm and 50 caliber fire and was sunk at
2240 hours on 19 Feb. One hour later, one probable Swatow class enemy
craft and one possible Swatow or Shanghai class vessel were engaged,
resulting in both enemy boats heavily damaged. The PTF force continued
south, passing between Hon Gio Island and the North Vietnam coast, when
they ware ambushed by one probable P-4 craft and one probable Shanghai II
class vessels. The P-R was heavily damaged and evaded, while the second
craft approached from Hon Gio Island and engaged one of the PTF's,
resulting in one friendly KIA and the enemy sunk.
Four PTF's have been modified to fire captured 122mm rockets at the
enemy. Two rocker tubes are mounted on each side of the PTP's. If all four
PTF's are employed, they possess the capability of firing sixteen 122mm
rockets simultaneously against a given target at a standoff range of
At total of six DODGE MARK missions were planned and five were
conducted during this period. On 29 Mar, DODGE MARK 12 was conducted
and made contact with one enemy who tried to escape and was killed.
One hand weapon and a small quantity of documents was captured.
DODGE MARK 17 was conducted in the DMZ on 20 Apr. No contact was
established, however, the PTF's conducted shore bombardment for 15
Typhoon Hester caused considerable damage to MACSOG maritime forces. Of
the five PTF's and three PCF's at Da Nang, two PTF's and 1 PCF were sunk
at the height of the storm. All boat crews were aboard the craft
with the engines running and mooring lines tended. They were successfully
riding out the storm when an adjacent pier parted its pilings, and was
driven into the three boats that sunk. Alert and timely actions on
the part of the Coastal Security Service and US Naval Advisory personnel
prevent serious injury and damage. Salvage operations were started
A NEWPORT CASINO operation with the mission of interdicting enemy
shipping off the North Vietnamese coast in the vicinity of Quang Khe was
conducted. Three PTF's participated in this operation, departing Da Nang
at 1800H on the evening of the 10th and proceeding north to a position
just north of Hon Gio Island. The PTF's then turned southwest and
commenced their area patrol. On 11 Feb, at 2330H, radar contact was made
and visual contact was made twenty minutes later with two junks. Each had
two masts and a single engine. A shot was fired across the bow of the
first junk at 0305H. The second boat attempted to evade and was taken
under fire by one of the PTF; causing one secondary explosion and setting
the junk on fire. The craft entered shallow water and beached itself. The
second junk was also taken under fire after it attempted to evade. The
vessel soon ceased its attempts to evade, allowing one PTF to come
alongside. A search party boarded the junk, captured six crew members and
approximately one kilogram of documents, and placed demolition charges
below deck. The junk was subsequently destroyed. Radar contact was
established with another target at 0340H, while the second junk was being
searched. One PTF took this craft, a TL-15 coastal cargo vessel, under
fire after it attempted to evade. The craft was 87 feet long and had a
displacement of approximately 100 tons. The ship sustained three large
secondary explosions and began to burn. After the fire subsided, one PTF
came alongside and placed a search party aboard. No live crew members were
found, but several charred bodies were observed. Cargo boxes were observed
on deck covered with tarps. The search party placed demolitions and
subsequently destroyed the ship. Later two injured crew members were
recovered from the water near the craft.
At 0500H on the 11th, the PTF personnel observed a SL-4 type trawler
showing lights. The PTF crew observed Chinese characters and a North
Vietnamese flag painted on its stack. Gun mounts were observed as the PTF
made a second pass and fired a warning shot across the trawler's bow. The
trawler attempted to evade and was taken under fire by all three PTFs. The
trawler returned fire and was observed to be communicating with a shore
station with signal lights. The trawler entered shallow water and one PTF
continued the engagement. However, when the trawler entered the south of
the Cue Gaing River the PTF was forced to break off the engagement. No
further targets were observed, and the PTF's returned to Da Nang arriving
at 1045H on the 11th. The prisoners were placed in isolation and
interrogated by ARVN intelligence personnel.
COMMENTARY AND ANALYSIS
MARITIME STUDIES BRANCH
One of the most productive branches in the SOG organization was
MACSOG-31, the Maritime Studies Branch. Possessed of an action arm known
as the Maritime Studies Group (MACSOG-37), which operated under the cover
name Naval Advisory Detachment, it had an excellent operational
record from inception in 1964 to disestablishment in 1972.
The majority of naval operations against North Vietnam in 1964 were
DeSoto patrols, which consisted of destroyers and aircraft operating in
the Tonkin Gulf disassociated from all OPLAN 34A MAROPS .
In the event of hostile attack, the patrol ships and aircraft were
directed to fire upon the hostile attacker with the objective of insuring
destruction. Ships were to pursue the enemy to the recognized three mile
territorial limit, while aircraft were authorized hot pursuit inside
territorial waters against surface vessels and into hostile airspace,
(which included NVN, Hainan Island, and Mainland China) against attacking
aircraft when necessary to achieve destruction of identified attacking
Originally, MAROPS had been designed to inflict psychological damage on
the North Vietnamese by demonstrating the NAD/CSS ability to strike
targets well above the 17th parallel. Destructive results and military
utility were considered secondary, though U.S. aircraft were later added
to the equation for cover operations above the 19th parallel.
Early OPLAN 34A operations were so successful that at one point the
U.S. government considered going public with a handful of tangible
victories in an effort to bolster the South Vietnamese and drum up popular
American support for the growing war effort.
Typical 1964-1972 MAROPS---fine tuning, as such, of more
conventional naval activities---consisted of shore bombardment
utilizing Russian-made 122mm rockets mounted aboard PTF's (the so-called
Nasty Class boats), junk captures, the kidnapping and disruption of the
Viet Cong Infrastructure (VCI) in coordination with Provincial
Reconnaissance Units below the 17th parallel, and Sea Commando Team
demolition sorties against coastal radar, highways, and bridges. While SOG
31/37 possessed the capability for inland operations, most of their in
shore coastal operations were of the shallow penetration variety,
Among the broad categories addressed in MACSOG-31 spot reports were
such items as North Vietnamese paramilitary activities, air defense,
conscription, coastal sea transportation, population controls, the
identification of dissident groups, effects of the war on the NVN economy,
and the governmental and popular reaction to friendly psywar activities.
SOG's concern over paramilitary activities extended beyond NVN support
for the Viet Cong. One of the earliest issues addressed by the Maritime
Studies Branch concerned the NVN effort to recruit and train Meo
tribesmen. Since South Vietnam's relations with its own Montagnards lay
somewhere between indifference and genocide, any attempt by NVN to win
over a people born and bred to environmental hardship had to be viewed as
a viable threat. SOG's experience with the capabilities of South Vietnam's
tribal peoples convinced them that this was a legitimate
In the area of psychological warfare, SOG's efforts revolved around
gift kits, pre-set radios, and actions against North Vietnam's fishing
industry. Despite great effort, the psywar operations garnered few
positive results and constituted one of the least successful aspects of
the covert maritime war.
MARITIME STUDIES BRANCH
(S) Maritime Studies Branch, MACSOG-31, continued to exercise staff
supervision and coordination for MACSOG covert maritime operations (MAROPS).
MAROPS were conducted by the Martime Studies Group, MACSOG-37, under the
cover name of Naval Advisory Detachment (NAD), Da Dang, in conjunction
with the Coastal Security Service (CSS) of the Vietnamese Strategic
Technical Directorate (SPD).
MACSOG-31 was disestablished on assumption of advisory status, 30 Apr
(TS) The type and tempo of MAROPS in 1971 and 1972 wars similar to
those of those of 1970 with the exception of operations north of the
17th parallel in Feb and Dec- 71 when the restrictions on northern
missions were temporarily suspended. MAROPS emanating from NAD continued
in the Military Region I (MR I) area, with the primary target shifting
from interdiction of NVA movement to disruption of the VC infrastructure
in coordination with Provincial Reconnaissance Units (PRU).
(S) The seven Patrol Boats, Fast (PTFs) and related equipment were
returned to US control.
(TS) In Jan 71, at the direction of CINCPAC, Maritime Studies Branch
developed five operation plans to support covert maritime operations
against North Vietnam.
1. MACSOG OPLAN 5-70 (CLAY DRAGON): Utilized PTFs to transport Sea
Commando Teams (SCTs) to designated targets along the North Vietnamese
coast. The SCTs were to conduct amphibious raids against transshipment
points to destroy/disrupt normal logistic flow.
2. MACSOG OPLAN 2-'71 (BOSTON ANTIQUE): Utilized PTF's to intercept
and destroy infiltration trawlers that had been designated a threat by
3. MACSOG OPLAN 3-71 (HAI CANG TUDO-2): Utilized PTF's to conduct
shore bombardment of designated transshipment areas along the coast of
4. MACSOG OPLAN 4-71 (GLYNN REEF): Utilized PTF's to destroy/disrupt
the North Vietnamese fishing industry along the coast of North Vietnam.
5. MACSOG OPLAN 5-71 (HAI CANG TUDO-1): Utilized PTPs for
interdiction of North Vietnamese coastal shipping along the coast of
(TS) In Feb 71, a JCS message authorized the execution of MACSOG OPLAN
5-71. The following two missions were conducted:
1. During the night of 10 to 11 Feb, three PTFs patrolling off
QUANG KHE, North Vietnam sank a motorized junk, an 8·ft TL-15 coastal
cargo vessel, and damaged another motorized junk and an SL-4 trawler.
2. During the night of 10 to 20 Feb four PTPs patrolling from
VINH to QUANG KHE, North Vietnam, sank a 60 ft patrol craft and a
130 ft SHANG HAI II, and damaged another SHANG HAI II and two SO-1
(TS) In mid-Feb 71, MACSOG-31 submitted to NAD a concept for mounting
communist-made 122mm rockets on the PTFs. NAD developed the idea and
installed the launchers by 1 Mar 71. Two salvos of four rounds could be
fired in a 15 minute period at a standoff range of 11,000 meters. The
addition of the launchers significantly increased the PTP coastal
bombardment potential. MACSOG OPLAN 3-1 was modified to include the new
(TS) During Dec 71, JCS authorized the execution of MACSOG 3-71. Two
missions were launched from Da Nang:
1. During the night of 26-27 Dec four PTFs were ordered to conduct
a 122mm rocket attack on QUANG KHE. The mission was aborted north
of the 17th parallel due to extremely heavy sea conditions.
2. During the night of 27-28 Dec, three PTF's were ordered to
conduct a 122mm rocket attack on QUANG KHE and DONG HOI. While
approaching the target the command PTF suffering an engineering casualty
and had to abort. The other two PTF's attempted to close the
target but were unable to do so due to the presence of enemy craft in
the firing area.
(S) Continuous refresher training at NAD emphasized gunnery and unit
tactics. CSS also began a program of officer billet rotation to
broaden the level of experience. A radar/electronics course was
conducted in Apr 71, and two Napier Deltic engine maintenance courses were
conducted September through December at the Ship Repair Facility, Subic
Bay, Republic of the Philippines.
SEA COMMANDO TRAINING
(C) SCT training was exercised through DODGE MARK operations.
These were supplemented by classes in ambush tactics, small arms firing,
map and compass reading, rubber boat operations, and physical
fitness. A training class in Oct-Nov 71 prepared 15 new Sea
Commandos for integration into the unit and brought the total number of
SCTs to five.
IN-COUNTY PTF OVERHAUL CAPABILITY
(S) With the exception of overhaul of Napier Deltic engines, complete
PTF repair and maintenance was conducted in Da Nang. The NAD mini-drydock
was returned to the Ship Repair Facility, Subic Bay, and NAD's PTF lift
requirement was assigned to the LSB, Da Nang.