Main contractor Leidos has announced that it is starting operational trials of the robotic sub-hunter it's building for DARPA. The Anti-Submarine Warfare Continuous Trail Unmanned Vessel (ACTUV) will take to the seas off the coast of San Diego, California in the coming months for tests of the unmanned ship's sensors, mission control hardware and software, and the autonomy system.

The 132-ft (42-m) autonomous trimaran, which was christened Sea Hunter on April 9, 2016, completed its initial sea trials earlier this year. These trials included executing a multi-waypoint mission without human intervention and tests of the Remote Supervisory Control Station (RSCS) designed to allow remote supervision and control of Sea Hunter from shore or a command vessel. In addition, Sea Hunter acted as the test bed for a towed airborne anti-submarine sensor array called TALONS.

Co-sponsored by DARPA and the Office of Naval Research (ONR), Sea Hunter is designed to track potentially hostile submarines for months at a time without a crew. Though the vessel is currently equipped with a temporary pilot house, later tests will have no personnel on board.

When it's in service, Sea Hunter will operate for around 30 to 90 days at sea without a crew, and will leave and return to port on its own. In addition, it's designed to operate safely and in accordance with maritime laws at only a tenth the cost of a conventional sub hunter.

Leidos says the sea trials will continue through the third quarter of 2017 as part of a two-year test program.

"Sea Hunter is at the forefront of new autonomy technologies for the US military," says Mike Chagnon, president of the Leidos Advanced Solutions Group. "The operational testing is designed to showcase the unprecedented capabilities that this type of unmanned vessel could offer our military forces."