Largest uncrewed ship

In April 2016, the US Defense Advanced Research Projects Agency (DARPA) launched the Sea Hunter, an uncrewed trimaran (a central hull with an outrigger on either side). At 40 m (132 ft) in length, it is the largest autonomous ocean vessel ever built. The Sea Hunter is a prototype for a new class of drone ship able to head thousands of miles out to sea to monitor ocean depths for submarines. However, unlike drone aircraft, which are remotely operated by human pilots, the Sea Hunter is given broad objectives and then uses radar and cameras to sense its environment and steer itself – much like a driverless car. Built by Vigor Industrial, of Portland, Oregon, USA, the ship has a top speed of 27 knots (31 mph or 50 km/h) and cost US$20 million (£15.2 m) to develop.