Two Marines wearing their wet suits and equipped with oxygen rebreathers swim above the surface as they prepare to mount their Diver Propulsion Device held near the boat by Marines assisting with the training at Courthouse Bay, Feb. 20. As members of 2nd Marine Special Operations Battalion, U.S. Marine Corps Forces, Special Operations Command with diving capabilities, they are required to maintain and hone their capability to conduct dive operations. On this day, the Marines used the DPD to assist them in navigating between points while submerged, allowing them to maneuver swiftly, accurately and without detection.