U.S. Marines with 2nd Reconnaissance Battalion, 2nd Marine Division (MARDIV), practice survival swimming techniques at the Courthouse Bay pool on Camp Lejeune, N.C., June 18, 2014. Marines and Sailors take a pre-dive class to strengthen their swimming abilities before attending the Naval dive school at the Naval Diving and Salvage Training Center in Panama City, Fla. (U.S. Marine Corps photo by Lance Cpl. Christopher A. Mendoza, 2nd MARDIV, Combat Camera/Released)