The US Navy has taken delivery of its first giant robotic submarine. Boeing’s Extra Large Uncrewed Undersea Vehicle (XLUUV), also known as “Orca,” has completed acceptance tests including extensive surface and underwater trials.

At a length of 85 feet (26 m) and a payload capacity of 8 tonnes (8.8 tons), Orca is the largest autonomous naval submarine ever built – in fact, it marks the entrance of a whole new class of vessel. It’s the first of four prototypes that have been ordered by the Navy for evaluation, and is based on Boeing’s Echo Voyager proof-of-concept XLUUV that first launched in 2017. That said, Orca is larger, with a modular design to tailor it to specific mission requirements.

Powered by a hybrid diesel/lithium-ion battery system, the boat can operate submerged for long periods, returning to the surface to use the diesel engine to recharge thanks to a retractable mast that also acts as a snorkel. The payload section can accommodate modules of up to 34 feet (10 m) in length, and the craft’s maximum speed is 8 knots (9 mph, 15 km/h). It has a range of 6,500 miles (10,500 km) and an endurance of an unspecified number of months. The autonomous systems handle navigation as well as missions in contested waters.

Though Orca is large for an autonomous submarine, it does appear small compared to conventional boats. This is deceptive, however, because Orca doesn’t need the life support systems, crew spaces, safety systems, or sound deadening of a sub carrying humans. As a result, it’s a much more compact vehicle that can cram a lot into a very small space.

“This is the culmination of more than a decade of pioneering work, developing a long-range, fully autonomous undersea vehicle with a large payload capacity that can operate completely independently of a host vehicle,” said Ann Stevens, Boeing Maritime and Intelligence Systems vice president. “I’ve had the distinct pleasure of witnessing our team bring this first-of-its-kind capability to life, and I’m proud of their innovation, perseverance and unwavering commitment which has yielded the most advanced and capable UUV in the world.”