ARTA BEACH, Djibouti (July 22, 2015) U.S. Marines with the 15th Marine Expeditionary Unit fill sand bags to construct an entry control point at a cantonment area ashore during sustainment training. Elements of the 15th Marine Expeditionary Unit are ashore in Djibouti for sustainment training to maintain and enhance the skills they developed during their pre-deployment training period. The 15th MEU is currently deployed in support of maritime security operations and theater security cooperation efforts in the U.S. 5th and 6th Fleet areas of operation (U.S. Marine Corps photo by Sgt. Steve H. Lopez/Released)