The Patrol Air Cushion Vehicle (PACV), also known as the Air Cushion Vehicle (ACV) in Army and Coast Guard service, was a United States Navy and Army hovercraft used as a patrol boat in marshy and riverine areas during the Vietnam War between 1966 and 1970. Six hovercraft were built, three for the Army and three for the Navy.
The military developed the PACV because its lack of draft meant that it could operate unimpeded in the shallow and reed-choked waters widespread in South Vietnam, most notably in the Mekong Delta and Plain of Reeds. The PACV was also found to be valuable because of its unusually high speed of 60 knots , faster than other watercraft in the conflict. However, it faced major drawbacks, including its high cost of $1 million and unreliability. During the conflict, two of the Army's three hovercraft were destroyed by the Viet Cong. The PACVs in Vietnam were considered "unsuccessful" in evaluations and were withdrawn in 1970.
PACVs were first deployed to Vietnam in May 1966 as PACV Division 107, Task Force 116, where they were used by the Navy for riverine patrol missions in the Mekong Delta and on the Mekong River. Often called "Pac Vees", they were armed with a .50 caliber machine gun mounted on a rotating platform in the front and two side-mounted M60 machine guns. In addition, the crew, and often US Army Special Forces and ARVN Rangers, riding on the side panels, employed assorted small arms such as M16 rifles and M79 grenade launchers as well as various other rifles, .45 pistols, light and medium machine guns, and grenades, although using small arms was dangerous because spent casings could fall into the propeller. The PACV was used to prevent Viet Cong infiltration from the sea and tidal areas along river mouths and deltas. It was especially useful in shallow marshy areas, especially the Mekong Delta, where other patrol boats such as the Patrol Boat, River or Patrol Craft Fast (Swift boat) could not go.
