A U.S. Marine assigned to 2d Low Altitude Air Defense, Marine Corps Air Station Cherry Point, N.C., makes his way down an obstacle on the Tarzan Course at the Officer Candidates School, Quantico, Va., Dec. 16, 2014. The course consisted of several obstacles that tested speed, coordination, and balance. (U.S. Marine Corps photo by Lance Cpl. Jacqueline A. Garcia/Released)