1st Battalion 1st Marines (1/1) is an infantry battalion in the United States Marine Corps based out of Camp Pendleton, California, consisting of anywhere from 800 to 2,000 Marines and Sailors, but the number fluctuates depending on the Battalion's mission. They fall under the command of the 1st Marine Regiment and the 1st Marine Division.The battalion has been organized around fire and maneuver warfare in tropical, woodland, desert, or Arctic environments. From at least 1989, the units were organized as such:Company A (AAV company) -trained for insertion by Amphibious Assault Vehicles.Company B (Boat company) - trained for insertion by boats (zodiacs). Also complimented with mountain warfare and various swimming specialties (CWSS, scout swimmer, etc.)Company C (Helicopter company) - trained for insertion by helicopter.Weapons company - usually split into 3 infantry platoons, each vehicle-borne through a variation of the Humvee.Mortar platoon - deploy and deliver 81 mm mortars via a M252 mortar system.Javelin platoon - employ the SMAW and, since its introduction in 2002, the Javelin weapons systems.CAAT platoon - includes heavy machine gunners (the 50-caliber machine gun or the Mk-19) and anti-armor missilemen (employ the TOW-2 missile).Headquarter and Service Company - The largest company, H&S includes the Battalion Commander and the Sergeant Major. It is organized as such:S-1 (personnel)S-2 (intelligence)S-3 (operations)S-4 (supply and logistics)S-6 (communications)BAS (Battalion Aid Station staffed by U.S. Navy Hospital Corpsmen)