The Unit Deployment Program (UDP) is a system for assigning deployments of the United States Marine Corps. To reduce the number of unaccompanied tours and improve unit continuity, the Commandant of the Marine Corps, (CMC) established it to provide for the deployment of units to the Western Pacific (WESTPAC) for periods of approximately six months. The initial program was a six-phased evolution that sequenced infantry battalions and aircraft squadrons/detachments into WESTPAC deployments, thus eliminating the 12-month permanent change of station assignments for personnel assigned to these units. The program commenced in October 1977 and has proceeded through the six phases. In August 1985, tank companies began phasing into the program but following Southwest Asia, were discontinued. In Fiscal Year 1987 (FY87) and FY88, Amphibious Assault Vehicle (AAV) companies and direct support artillery batteries were phased in and later, Light Armored Reconnaissance (LAR) companies were also included in the program. The Marine Corps’ objective is to adhere as closely as possible to a six-month period of deployment away from a unit's Continental United States (CONUS) home base. In the case of Hawaii-based infantry battalions, which employ a three-battalion rotation base, a seven-month period of deployment is executed to support the Unit Cohesion Program and efficient staffing of first term Marines. It must be understood, however, that shipping or airlift schedule variations, and exercise or contingency operations will occasionally necessitate longer or shorter deployments for participating units. It is imperative that all personnel involved in these deployments be kept fully informed of planned deployment duration and subsequent deployment schedule changes.