The US Navy’s Robotic Sea Hunter Warship Uses AI In Place of a Crew

The swells in the middle of the North Pacific were reaching nine feet when one of two engines on the diesel-powered U.S. naval ship called Sea Hunter shut down. About 1,500 nautical miles from its home base in San Diego, the 132-foot-long craft, which had been cruising at 10 knots, couldn’t send a member of its crew to check out the problem—because it didn’t have a crew.

Sea Hunter’s sleek, spiderlike silhouette, with a narrow hull and two outriggers, is a prototype of what could be a new class of autonomous warships for the U.S. Navy. Its artificial intelligence–based controls and navigation system, designed by Leidos Holdings, a defense contractor based in Reston, Va., were seven years in the making. And this maiden voyage—a more than 4,000-mile roundtrip to the giant Pearl Harbor naval station—was its first major proof of concept.

Nothing like this had ever been attempted before. And while the A.I. systems that keep the ship on course and help it avoid collisions with other vessels were working exactly as advertised, a glitch in its mechanical systems threatened to scuttle the trip—a reminder to tech geeks that no matter how advanced the technology, mundane mechanical problems can bring a project down.

A group of 14 support staff in a trailing escort ship sprang into action. Keith Crabtree, a systems engineer with Leidos, and other staff jumped into a rigid inflatable boat and zipped over to Sea Hunter. Crabtree, who had helped put the ship through its paces in the calmer waters of San Diego Bay, says he wasn’t worried about the swells as he rode across the waves to Sea Hunter. The triple-hulled design of the prototype, inspired by the Polynesian waka canoe, offered a more stable perch than the bouncing journey aboard the escort ship.

“We were in for a smoother ride than what we had been enduring,” Crabtree recalls. A simple software fix corrected the problem, and after docking at Pearl Harbor, Sea Hunter completed the 10-day return trip without incident.

Sea Hunter, it bears noting, is the first autonomous ship to make an ocean crossing and, remarkably, the first Navy ship designed from scratch by Leidos.

Little known outside government contracting circles, Leidos, then dubbed Science Applications International Corp. (SAIC), was founded 50 years ago by Robert Beyster, a brilliant and entrepreneurial physicist who had worked on the hydrogen bomb at the Los Alamos National Laboratory. An avid sailor and a friend of yacht-racing captain Dennis Conner, Beyster tasked SAIC to develop software to model improved hull designs after Conner’s squad lost the America’s Cup to an Australian team led by Alan Bond in 1983—the first American loss in the race’s 132-year history. Connor regained the Cup the following year.

That expertise came in handy on future projects with the Navy but didn’t publicly reemerge until 2012, when a $59 million contract win to develop an autonomous ship put the software front and center once again. For Sea Hunter, the company also drew on expertise gained from many loosely related projects, including developing underwater sensors for the Navy, performing coastline surveys for the National Oceanic and Atmospheric Administration, and conducting A.I. work to process satellite imagery.