The tank and assault amphibian vehicle OccFld includes operation, employment, maneuver, and maintenance of tracked vehicles in the combined arms environment during both amphibious assaults and subsequent land operations ashore. Qualifications required include basic mechanical aptitude and the ability to perform harmoniously with others in the confined area inside combat vehicles. The duties involved are incident to the operation, employment, maneuver, and maintenance of tanks and assault amphibious vehicles. Formal schooling is provided to Marines at both the entry level and at the appropriate time in career development. Marines entering this OccFld receive MOS 1800, Basic Tank and Assault Amphibious Vehicle Crewman. After entry into OccFld 18 and assignment of a basic 1800 MOS, personnel specialize in either the M1A1 tank or the assault amphibious vehicle are assigned MOS 1812, or 1833 respectively.
Below are the Marine Corps Enlisted Military Occupation Specialties which are organized under this occupational field:
1812 --M1A1 Tank Crewman
1833 --Assault Amphibious Vehicle (AAV) Crewmember
1834 --Expeditionary Fighting Vehicle (EFV) Crewman

