U.S. Navy Master-at-Arms 1st Class Brian Heinkel, on the boat, assigned to a harbor patrol unit, explains the duties of harbor security to children with the U.S. Navy League Cadet Corps, Battleship Missouri Division-Hawaii April 13, 2013, at Ford Island, Joint Base Pearl Harbor-Hickam, Hawaii. Masters-at-arms assigned to security forces, harbor patrol and military police working dog units provided demonstrations of their daily operations. (U.S. Navy photo by Mass Communication Specialist 3rd Class Diana Quinlan/Released)