MSubs

Market context

MSubs designs and builds manned and unmanned underwater vehicles for defence, testing and subsea missions. Its Royal Navy work includes the CETUS extra-large uncrewed underwater vehicle, formally named XV Excalibur, for large autonomous-underwater-platform trials.

Products

• XV Excalibur / CETUS

Facts

• Website: https://msubs.com/
• HQ: Plymouth, United Kingdom
• Segment: maritime robotics

Commercial

2 commercial events; 2 contract awards; latest event 2026-06-25

• 2026-06-25 - Contract award - MSubs receives UK SDA trial contract for CETUS XLUUV - source: ukdefencejournal.org.uk
• 2020-03-05 - Contract award - MSubs wins Royal Navy XLUUV test submarine contract - source: gov.uk

Events

• 2026-06-25 - Contract Award - MSubs receives UK SDA trial contract for CETUS XLUUV - The trial phase covers CETUS payload testing, underwater-autonomy de-risking and military-utility evaluation. XV Excalibur is the Royal Navy XLUUV developed through Project CETUS with MSubs. GOV.UK describes Excalibur as a 12 m, 19 tonne extra-large uncrewed…
• 2025-12-11 - Production Milestone - MSubs-built XV Excalibur handed over to Royal Navy - XV Excalibur is a 12-metre, 19-tonne extra-large uncrewed underwater vehicle. The vehicle was developed by the Submarine Delivery Agency in partnership with MSubs under Project Cetus. Acceptance trials followed its February 2025 launch and preceded Royal Navy…
• 2020-03-05 - Contract Award - MSubs wins Royal Navy XLUUV test submarine contract - The project converted an existing crewed submersible with autonomous control systems. The program explored larger uncrewed underwater vehicles for surveillance, reconnaissance and anti-submarine warfare. The customer-backed award strengthens MSubs's position…

Customers and deployments

• Delivered Xluuv Count - 1 XV Excalibur XLUUV delivered - 2025-12-11 - Royal Navy - uncrewed underwater vehicle test and evaluation - The MSubs-built XV Excalibur extra-large uncrewed underwater vehicle was handed over t…
• Initial Contract Value Gbp - GBP 1 million initial contract - 2020-03-05 - Royal Navy - extra-large autonomous underwater vehicle development - MSubs received an initial GBP 1 million DASA contract to build an extra-lar…