U.S. Navy Lt Scott Keelan (left) briefs sailors of Patrol Squadron 46 aboard a P-3 Orion aircraft prior to a sinking exercise Sept. 13, 2016, at Andersen Air Force Base, Guam, during Valiant Shield 2016. SINKEX provided service members the opportunity to gain proficiency in tactics, targeting, and live firing against a surface target at sea. Valiant Shield is a biennial, U.S. -only field-training exercise with a focus on integration of joint training among U.S. forces. (U.S. Marine Corps photo by Sgt. Justin Fisher)