150922-N-PO203-127 PATUXENT RIVER, Maryland (Sept. 22, 2015) A submerged threat identification and neutralization (STID-N) vehicle conducts a survey of the sea wall adjacent to the Naval Test Pilot School during the Office of Naval Research-sponsored demonstration of unmanned undersea vehicles (UUV) at Naval Air Station Patuxent River, Md. The event, PAX River 2015, brings together 150 participants, 26 technology teams and unmanned systems to jointly explore UUV technologies in common, at-sea environments. (U.S. Navy photo by John F. Williams/Released)