WEST BETHESDA, Md. (June 26, 2013) Competitors prepare their submarines during the 12th International Human-Powered Submarine Races (ISR) being held in the David Taylor Model Basin at the Naval Surface Warfare Center Carderock Division. The mission of the ISR is to inspire students of various engineering disciplines to explore broad areas of underwater technology advancement, foster advances in subsea vehicle hydrodynamic, propulsion and life support systems and to increase the public awareness of the challenges people face in working in and exploring the ocean depths. (U.S. Navy photo by John F. Williams)