U.S. Air Force Staff Sgt. Shawn McNamara, 633rd Security Forces Squadron boat patrolman, drives the boat during a routine patrol in the Back River, Va., Aug. 17, 2016. The boat patrol unit patrols the water as a physical deterrent to prevent unauthorized access to Langley Air Force Base. (U.S. Air Force photo by Airman 1st Class Tristan Biese)