STRAIGHT UP U.S. Navy sailors climb a net wall as part of an obstacle course on Naval Amphibious Base Coronado in San Diego, Calif., June 10, 2010. The obstacle course is a component for the training of sailors in special operations and expeditionary forces. SHARE: Download: Full Size (0.09 MB) Credit: VIRIN: 773716-H-HAR55-981.jpg Photo Gallery