According to a recent Royal Navy news update, the Royal Navy has unveiled its first uncrewed submarine, named XV Excalibur, at HMNB Devonport. The 12-metre vessel, displacing 19 tonnes and measuring two metres across, marks a significant milestone in the UK’s underwater warfare capabilities.
The Excalibur is the culmination of the three-year-long Project Cetus, which aimed to explore advanced uncrewed underwater systems. It is the largest uncrewed underwater vessel trialled by the Royal Navy to date and was unveiled during a formal naming ceremony attended by 200 guests, including Rear Admiral James Parkin, Navy Director Develop, and representatives from AUKUS nations.
The Excalibur will undergo extensive sea trials over the next two years, gathering critical data and helping develop the Navy’s operational understanding of large uncrewed underwater systems. This testing phase aims to enhance the Royal Navy’s ability to integrate advanced technologies into mixed fleets of crewed and uncrewed vessels.
The craft was built by MSubs, a Plymouth-based company specialising in automated submersibles. Commodore Marcus Rose, deputy director Underwater Battlespace Capability, highlighted the importance of the project:
“The naming of Excalibur is a significant milestone for the Royal Navy and the upcoming sea trials will allow us to rapidly develop our understanding of operating uncrewed vessels of this size underwater,” said Commodore Rose.
Rear Admiral Parkin also stressed the importance of practical testing, stating:
“In our journey towards autonomy and mass, it is vital we learn by doing, and Excalibur will be our mechanism for understanding the complexity and challenges of operating a future team of crewed and uncrewed vessel and systems underwater.”
Officially classified as an Extra-Large Uncrewed Underwater Vessel (XLUUV), Excalibur will join the Fleet Experimentation Squadron under the Disruptive Capabilities and Technologies Office. The squadron already includes the surface ship XV Patrick Blackett, with Excalibur acting as a testbed for cutting-edge maritime technology.
The vessel will primarily focus on Intelligence Surveillance and Reconnaissance (ISR) and stealth operations, leveraging its capacity to carry bespoke payloads. As a demonstrator platform, it will not carry out operational duties but will instead shape the future of the Royal Navy’s mixed fleet approach.
Excalibur’s name draws on the legendary sword of King Arthur, reflecting the vessel’s pioneering role in the Navy’s transition to advanced autonomous warfare. The name also pays homage to a high-speed experimental submarine tested by the Navy in the 1950s and 60s.
Following its delivery earlier this year, Excalibur has already completed Harbour and Sea Acceptance Trials (HATs and SATs) at Devonport Naval Base. Rear Admiral Parkin summarised the project’s ambition:
“This is an exciting day for the Royal Navy, the UK Armed Forces, and my team in particular as today marks the moment at which we take ownership of this superb vessel for the first time.”
and replaces entire surface fleet with one robot sub.
This remote sub could be the most significant RN development in a hundred years. We know just how brilliant the WW2 Mini Subs were and size does matter. The scope for these subs is huge a small but well-distributed fleet across the World would be most effective.
Good Day! Develop and expand this Technology to our advantage! One should also develop an armes variant to attack at will.
An armed variant
I wonder if it would be possible for surface warships to carry something like one of these routinely, as a countermeasure ready to be deployed at the first hint that there may be an unfriendly sub around? At the very least it might distract the enemy.
I thought we already had a UUV called Manta.
Is this just bigger?