Operation Overview: The 1 st Battalion, 5 th Marines arrived in Southeast Asia in 1965, conducting many short but difficult amphibious or heli-borne assaults ashore against suspected Viet Cong strongholds. These amphibious operations were launched from their shipboard base aboard the USS Princeton (LPH5), in the South China Sea , off the coast of the Republic of South Vietnam . In December 1965, 1/5 landed and stayed ashore for awhile, this time at Chu Lai. From their base at the Chu Lai airfield, 1/5 conducted defensive operations for the security of the critically important airbase, as well as many squad, platoon and company-sized offensive operations.
Operation JACKSTAY was an amphibious operation, launched from the USS Princeton, that utilized surface borne and helicopter borne assault forces. D-day for this search and destroy mission: 26 March 1966 . The scheme of maneuver dictated two phases over a period of about ten days. Phase One: a provisional rifle company lands over Red Beach and establishes blocking positions, and lands an artillery battery over Red Beach as well. At the same time, the Marines of Charlie Company heli-lifted into LZ Sparrow and established blocking positions; Alpha Company lands in LZ Rob in to secure the LZ and provide a defensive perimeter for subsequent landings, and Bravo, Delta and H & S Companies and other combat support and service support elements follow Alpha Company into LZ Rob in. The initial phase of the operation focused on securing three objectives within approximately two days. Phase Two operations would largely depend on the situation as it developed, the availability of helicopters and surface craft, and the time and space factors dictated by the terrain and weather.
1/5 landed and spent almost two weeks in the swamps of the Rung Sat Special Zone, a swampy area intersected by waterways, during Operation JACKSTAY.
As planned, on 6 April 1966 , the Marines of 1/5 withdrew from the Rung Sat Special Zone and went back aboard the USS Princeton. According to the Combat After-Action Report for Operation JACKSTAY, compiled by Lt. Col. Coffman, CO of 1/5, at least 63 Viet Cong were killed by 1/5 Marines and probably 60 more were either killed or wounded. In addition, a substantial amount of enemy equipment and material was captured and/or destroyed by BLT 1/5. Overall, the Marines of 1/5 had accomplished their mission with great success, while taking very few casualties. The Rung Sat Special Zone turned out to be a very difficult area to conduct combat operations, but the Marines were up to the task.