The sword under the sea: Royal Navy's first uncrewed submarine called Excalibur

The Royal Navy has unveiled the name of its new submarine to be used for AI and Autonomation testing – XV Excalibur.

This experimental submarine is the culmination of the three-year-long Project Cetus and is set to pave the way so the UK can operate in the underwater battlespace.

At 12 metres long, two metres wide and displacing 19 tonnes, Excalibur is described as an extra-large, uncrewed, underwater vessel, and is the largest uncrewed submarine ever trialled by the Royal Navy.

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Even just 20 years ago, this crewless craft would have seemed like science fiction. 

XV Excalibur received a traditional welcome to the Royal Navy at HMNB Devonport.

Rear Admiral James Parkin said the technology would exponentially increase the scale of operations. "It's a wood-to-steel moment," he explained.

"It's a sail-to-steam moment because for the first time ever we can create, build and operate a Navy that's the equivalent of a navy that's 10, 20, 50 times the size of today's Navy."

According to project officer Commodore Marcus Rose, Excalibur will feature anti-submarine warfare sensors, mine warfare sensors and things that we can use for the protection of critical underwater infrastructure.

"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," he said.

"The lessons learnt from this exciting programme will build on our experience from existing programmes, such as the Mine Hunting Capability programme, to inform more extensive use of these technologies in a mixed force of crewed and uncrewed systems.

"In our journey towards autonomy and mass, it is vital we learn by doing."

After being rigorously trialled for two years, Excalibur will be able to operate autonomously and will have experienced many different payloads. 

Excalibur won't enter service herself, but will help forge forwards uncrewed sub-sea systems for years to come.