SHALLOWS

Coastal Warfare, 1965–1966
The loss of two PCFs in just two months revealed the vulnerability of these unarmored
patrol craft to mines and rocket attacks. By the end of 1966 a line of demarcation was drawn
across the mouth of each river, and PCFs were not permitted to cross into rivers without special
consent or unless involved in hot pursuit. In August 1966 the Naval Research Laboratory
commissioned a study to explore the feasibility of installing enough armor on the PCF to give
it limited protection against .30- and .50-caliber machine guns and 57mm rockets. The study,
conducted by Westwood Research, concluded that the armor protection would have reduced
the speed of the PCF considerably and so the effort was abandoned. 136
The study also severely criticized the PCF’s lack of seaworthiness, noting that three PCFs
(14, 76, and 77) sank in rough seas during the course of the war. “The Swift boat performed
well during nine months of the year,” concluded the Westwood study, “but for the remaining
three months during high seas the craft was virtually useless for the tasks it was assigned. The
PCF was almost completely ineffective in seas greater than five feet in height, and those seas
occur frequently in some coastal sectors during the monsoon seasons” 137 The PCFs often had
to abandon their patrol sectors and seek shelter from the monsoons. Rear Admiral Ward was
so disappointed in the performance of the PCFs that he later regretted his decision to purchase
them. “Because of those sea conditions off the coast, I regretted not getting larger ones,” he
said. 138 Ward instead relied heavily on Coast Guard WPBs to patrol areas most affected by
monsoons—yet another reason why most of the major steel-hulled intercepts were made by
these boats and not by the Swifts.
Despite the problems associated with the PCFs, Market Time as a whole proved generally
effective in curbing infiltration by steel-hulled trawlers. In the end, the stronger elements of
the barrier compensated for the weaker ones. Perhaps the greatest unsung heroes of the barrier
patrol were the patrol aircraft that performed long, often very dull search missions over the South
China Sea. Of the 17 trawlers attempting to infiltrate before 1970, aircraft initially detected all
but two. 139 It was difficult indeed for any large steel-hulled ship to slip through Market Time’s
powerful net of airborne radars, and those that did would inevitably be picked up by a galaxy
of shipboard radars. Historian Mark Moyar, who examined North Vietnamese naval records,
concluded, “Market Time swiftly brought Hanoi’s maritime infiltration operations to ruin, as
if the stopper had been pulled and all of South Vietnam’s coastal waters had gone down the
drain.” He based this assessment on Communist records, which indicated that between February
1962 and February 1965 North Vietnamese navy trawlers made 89 trips to South Vietnam and
succeeded in delivering their cargoes on 86 occasions. By comparison, from the beginning of
Market Time in March 1965 to the end of the war in April 1975, North Vietnam would make
only 80 supply voyages, and of this number only 14 would reach their destination. 140
Market Time was much less successful in stemming the flow of supplies coming into the
country on smaller wooden-hulled junks. The Center for Naval Analyses found that in 1966
U.S. Market Time forces searched only about 15 percent of the junks they detected at sea and
that the probability of discovering a wooden-hull infiltrator from outside South Vietnam among
79