U.S. Marines run towards their security positions. U.S. Marines with Charlie Company, 1st Battalion, 1st Marine Regiment, 13th Marine Expeditionary Unit run towards their security positions while fellow Marines offload food and water from an aircraft during a humanitarian assistance survey team scenario on San Nicholas Island, Calif., on Dec. 9, 2008. The 13th Marine Expeditionary Unit is conducting a certification exercise to prepare for an upcoming deployment. SHARE: Download: Full Size (0.08 MB) Credit: VIRIN: 126526-I-GLE21-550.jpg Photo Gallery