OP-31 Maritime Studies Branch - Code Name: "Plowman"
January 1965, the Maritime Operations Section was establish as the staff at MACV-SOG headquarters for its operational arms, the NAD. As with the Airborne Operations, the inception of Rolling Thunder lead to a change in mission from punitive and harassment operations to intelligence collection and shipping interdiction.
Six Nasty PTF’s and three Swift PCF’s were in the inventory at the beginning of the year. Four new PTF’s were added for a total of ten. However due to maintenance problems sit PTF’s and two Swifts were normally all that were operational at any one time. During the year the number of Vietnamese Sea Commandos declined to 148. MAROPS conducted 155 missions in 1965 during which fifty North Vietnamese vessels were destroyed and nineteen were damaged, including three naval patrol craft. There were 59 shore bombardments and 25 psychological harassment missions. 1,000 radio 28,742 gift kits and 1,124,600 leaflets were distributed. CSS casualties for the year were one man killed in Action and eighteen wounded. PTF 4 lost on an operations and the gasoline-powered Nasty’s that had arrived during 1963, (PTF’s 1 and 2 were stripped and suck for target practice).
South Vietnamese Role
April 1, 1964 the Special Branch for Clandestine Operations of the Technical Exploitation Service that have been tasked covert operations and intelligence gathering was split into two sections. 1. Strategic Exploitation Service (SES) became MACV-SOG Vietnamese counterpart. One of it’s elements was the Coastal Security Service (CSS) that was to conduct maritime operations for OPLAN 34A. Secondly the Vietnamese Liaison Service, which conducted intelligence collection and clandestine Operations in Laos.