I give you, DARPA’s robot subchaser, Sea Hunter, testbed of the ACTUV program, which is now part of ONR.
From DARPA:
DARPA has successfully completed its Anti-Submarine Warfare (ASW) Continuous Trail Unmanned Vessel (ACTUV) program and has officially transferred the technology demonstration vessel, christened Sea Hunter, to the Office of Naval Research (ONR). ONR will continue developing the revolutionary prototype vehicle—the first of what could ultimately become an entirely new class of ocean-going vessel able to traverse thousands of kilometers over the open seas for month at a time, without a single crew member aboard—as the Medium Displacement Unmanned Surface Vehicle (MDUSV).
The handover marks the culmination of three years of collaboration between DARPA and ONR that started in September 2014. An April 2016 christening ceremony marked the vessel’s formal transition from a DARPA-led design and construction project to a new stage of open-water testing conducted jointly with ONR. That same month, the vessel moved to San Diego, Calif., for open-water testing.
ONR plans to continue the aggressive schedule of at-sea tests to further develop ACTUV/MDUSV technologies, including automation of payload and sensor data processing, rapid development of new mission-specific autonomous behaviors, and exploring coordination of autonomous activities among multiple USVs. Pending the results of those tests, the MDUSV program could transition to U.S. Navy operations by 2018.