Construction Electrician Constructionman Trace Martin, and other Sailors assigned to Naval Mobile Construction Battalion (NMCB) 11, perform contact engagement drills in preparation for their role as the opposing force for an upcoming Marine training operation during Exercise Valiant Shield 2016 in Tinian, Commonwealth of the Northern Mariana Islands (CNMI), Sept. 18, 2016. 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. (U.S. Navy Combat Camera photo by Mass Communication Specialist 1st Class Benjamin A. Lewis/Released)