U.S. Marine Corps Staff Sgt. Nicholas Clausing, left,

U.S. Marine Corps Staff Sgt. Nicholas Clausing, left, a crewmaster with Marine Aerial Transport Refueler Squadron (VMGR) 152, signals the time to a U.S. Marine with Marine Corps Forces Special Operation Command, during unit-level training called El Centro Horizon at Marine Corps Air Station Camp Pendleton, California, Dec. 7, 2017. VMGR-152 conducts air deliveries in order to mass combat troops and supplies in areas unsuitable for landing the KC-130J Hercules aircraft. El Centro Horizon provides VMGR-152 with more opportunities to increase squadron combat readiness through the diverse training ranges available in the area. (U.S. Marine Corps photo by Cpl. Carlos Jimenez)