GULF OF ADEN Sailors sort mail in the hangar bay of Wasp-class amphibious assault ship USS Essex during a replenishment-at-sea with Military Sealift Command dry cargo and ammunition ship USNS Carl Brashear. Essex is the flagship for the Amphibious Ready Group and, with the embarked 15th Marine Expeditionary Unit, is deployed in support of maritime security operations and theater security cooperation efforts in the U.S. 5th Fleet area of operations.