Navy Lt. Craig Stocker, center left, and Navy Lt. j.g. Trey Browning, center right, collect training data and monitor the movement of ships during an anti-submarine exercise aboard the guided missile destroyer USS Stockdale during a Cruiser-Destroyer, Surface Warfare Advanced Tactical Training exercise in the Pacific Ocean, April 18, 2018. Stocker and Browning are warfare tactics instructors attached to the Surface and Mine Warfighting Development Center. Navy photo by Petty Officer 2nd Class Amanda A. Hayes