California may be the home of Google’s robotic cars, but just off the coast, DARPA is testing technology that puts the search giant’s trundling little autonomous marshmallows to shame.

The defense agency’s robotic ship—the Continuous Trail Unmanned Vessel, to those in the know—has been running sea trials on its new radar system. But the technology doesn’t sit aboard the ship: instead, it’s slung behind it on a parasail in order to reach heights of between 500 and 1,500 feet.

Tests show that the extra altitude boosts the radar’s effectiveness, vastly extending its range beyond what's possible when it’s simply fixed to a ship’s mast. DARPA believes this is what the future of naval warfare looks like: drone boats out patrolling in potentially hostile waters, while manned boats remain out of harm’s way for as long as possible.

DARPA isn’t alone in building robotic ships, though. Between initiatives to develop autonomous taxi boats in Amsterdam, data-collecting trimarans in California, and autonomous tugs in Boston, self-sailing boats are taking to the water all over the world.

(Read more: DARPA, “Fleets of Robotic Boats Are Getting Ready to Set Sail”)