An amphibious assault vehicle with 3rd Amphibious Assault Battalion drives onto a roll on/roll off discharge facility attached to USNS Sgt. William Button near Camp Pendleton, Calif. during Pacific Horizon 11, March 3. Pacific Horizon 11 provides 1st Marine Expeditionary Force and the Navy's Expeditionary Strike Group-3 the opportunity to exercise essential core competencies at the brigade level to rapidly respond to an emerging crisis with a flexible, full spectrum capability.