Keywords: Liberdade XRay underwater glider.jpg Pictured is the XRay1 a Liberdade class underwater glider which is an autonomous underwater glider vehicle originally developed by research institutions and the US Navy w Office of Naval Research to track diesel powered submarines They are now used to study marine mammals http //www onr navy mil/~/media/Files/Fact 20Sheets/advanced_underwater_glider ashx 2006-04-19 w Office of Naval Research Clipped from ONR pdf file see link above PD-USGov-Military-Navy Underwater gliders Autonomous underwater vehicles Submarine detection |