U.S. Army Staff Sgt. Ray Cortwright, 74th Engineer Detachment (Dive), 30th Engineer Battalion, 20th Engineer Brigade dive supervisor, adjusts dive equipment before a training scenario at Fort Eustis, Va., March 12, 2014. Divers must dive once every 90 days and at least eight times a year to remain proficient. (U.S. Air Force photo by Senior Airman Austin Harvill/Released)