UK Awards £6.7 Million Contract for Further XV Excalibur XLUUV Trials

The UK Submarine Delivery Agency has awarded Plymouth-based M Subs a £6.7 million contract to conduct further trials and evaluation of the CETUS extra-large uncrewed underwater vehicle, formally named XV Excalibur. Running from June 2026 to May 2028, the programme will focus on reducing technical risks associated with underwater autonomy and demonstrating the platform’s military utility through payload testing, sea trials and operational evaluation.

XV Excalibur is a 12-metre, 19-tonne XLUUV developed for the Royal Navy and assigned to the Fleet Experimentation Squadron under the Disruptive Capabilities and Technologies Office. The platform is intended to support experimentation in intelligence, surveillance and reconnaissance, stealth operations and modular payload deployment. Although it will not initially perform operational missions, the vessel is expected to inform future concepts for integrating crewed and uncrewed systems within the Royal Navy’s undersea force structure.

The contract was awarded directly to M Subs because the company is the sole designer and manufacturer of CETUS and holds the technical knowledge required to operate the vessel safely during trials. The programme will build on earlier Project Manta testing conducted with a smaller autonomous underwater vehicle and will support the broader introduction of XLUUV capabilities into Royal Navy service. Following the initial trials, the SDA plans to expand competition for long-term operation and future payload development.