DARPA's 'Hydra' would be an undersea drone carrier[ Wed, 24 Jul 2013 00:55:47 GMT ]Unmanned aerial vehicles, or UAVs, are in the news constantly, but what about unmanned underwater vehicles? They could also be important in both war and peace, which is why the Defense Department's research arm, DARPA, is looking into a mobile submarine base from which to launch drones.