U.S. Air Force Airmen backstroke as a unit during a water survival training refresher course at Davis-Monthan Air Force Base, Ariz., Jan. 5, 2015. The group activity focused on getting aircrew members accustomed to working together while in water so they are able to preserve energy in the event of a ditched aircraft. (U.S. Air Force photo by Airman 1st Class Chris Drzazgowski/Released)