Participants of the 15th annual Go Tri Sports South Carolina Triathlon Series exit the pool after the 500-meter portion in the Combat Swim Tank aboard Marine Corps Recruit Depot Parris Island, S.C., March 16, 2012. The triathlon consisted of a 500-meter pool swim, 10-mile bike course, and a 5k run. (U.S. Marine Corps photo by Cpl.Aneshea S. Yee/Released)