U.S. Navy Electrician's Mate 2nd Class Marquis Williams, assigned to the guided missile destroyer USS Mustin (DDG 89), stands watch inside the ship's engineering control center in the Pacific Ocean Sept. 22, 2014, during Valiant Shield 2014. Valiant Shield is a biennial U.S. Air Force, Navy and Marine Corps exercise held in Guam, focusing on real-world proficiency in sustaining joint forces at sea, in the air, on land and in cyberspace.