Following a series of successful sea trials, DARPA has handed its experimental autonomous warship over to the US Navy. The Anti-Submarine Warfare (ASW) Continuous Trail Unmanned Vessel (ACTUV) "Sea Hunter" technology demonstrator was formally transferred to the Office of Naval Research (ONR) for further development of what could potentially be the first of a new class of ocean-going ships called Medium Displacement Unmanned Surface Vehicles (MDUSVs).

With its pilot house, the 132-ft (42-m) ACTUV looks like an odd naval trimaran, but the crew accommodation is only a temporary structure for the robotic craft's human overseers during sea trials. When it's fully developed, it will be a sub hunter capable of leaving port on its own, carrying out its mission across thousands of miles of open sea, and then returning home after three months – all without human intervention. It can even deal with other ships in the area safely and in accordance with maritime laws at only a 10th the cost of a conventional sub hunter.

In cooperation with ONR, DARPA has been developing Sea Hunter since 2012 as a way of providing less expensive autonomous ships to act as a countermeasure against modern, quiet diesel submarines. However, the general MDSUV class is also considered a way to move away from the tendency of advanced navies to consist of a handful of highly advanced warships and toward a more balanced fleet with smaller, unmanned "pawns" augmenting the manned "kings" and "queens."

Sea Hunter began sea trials in July 2016 off the coast of San Diego, California, with further testing in October of that year of the vessel's sensing and autonomy suites. Beginning in February 2017, a series of increasingly challenging, realistic tests were performed to demonstrate the technology demonstrator's ability to comply with the International Regulations for Preventing Collisions at Sea (COLREGS). In addition, the ACTUV/MDUSV design was tested in regard to its ability to operate with modular payloads as well as using DARPA's Towed Airborne Lift of Naval Systems (TALONS) and a mine countermeasures (MCM) payload.

"ACTUV's move from DARPA to ONR marks a significant milestone in developing large-scale USV technology and autonomy capabilities," says Alexander Walan, a program manager in DARPA's Tactical Technology Office (TTO). "Our collaboration with ONR has brought closer to reality a future fleet in which both manned warships and capable large unmanned vessels complement each other to accomplish diverse, evolving missions."

DARPA says that ONR will carry out additional sea trials to test automated payload and sensor data processing, rapidly developing new mission-specific autonomous behaviors, and exploring autonomous coordination among multiple unmanned surface vessels. If these are successful, the MDUSV could enter US Navy operations sometime this year.

The video below shows Sea Hunter going through her paces.

Source: DARPA