GULF OF ADEN Boatswain's Mate 1st Class Devona Martinez instructs a Sailor how to utilize a canteen during a chemical, biological and radiological drill in the gym of Wasp-class amphibious assault ship USS Essex. 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.