British unmanned systems manufacturer MSubs has launched Cetus, the UK Royal Navy’s first Extra Large Underwater Autonomous Vehicle (XLUAV) technology demonstrator.  At 12 m in length, 2.2 m in diameter, and weighing up to 25 tonnes with a full test payload, the demonstrator is claimed to be the largest and most complex crewless submersible procured by a European navy to date.  MSubs of Plymouth was awarded the £21.5 million contract to manufacture Cetus in November 2022.  

Once delivered, the vessel will be deployed independently to secure the country’s critical infrastructure and monitor sub-sea activities across its territories. The XLAUV will sail on other missions supporting the navy’s existing crewed submarines, including the Astute-class nuclear-powered submarines and their successors.

The submarine can cover a range of about 1,000 miles (1,609 kilometers) in a single mission, has an endurance of up to five days, and incorporates design for additional capacity and power supply if needed.

The UK Ministry of Defence noted in the effort’s announcement in 2022 that the battery-enabled XLAUV “will be able to dive deeper than any vessel in the current submarine fleet” and will also be used to “experiment and build cutting edge technologies and capabilities around, encouraging innovation and developing best practice.”

Royal Navy launches New Large unmanned submarine, CETUS, The Largest Drone Submarine In Europe

Thanks to Alaric Bond for contributing to this post.