MilitaryProject Cetus
Submarineconfirmed
Project Cetus is a United Kingdom programme to develop and trial an extra-large uncrewed underwater vehicle (XLUUV) for the Royal Navy. Named after Cetus, a mythological sea monster, the project was funded through the Royal Navy's Anti-Submarine Warfare Spearhead programme and delivered by the Submarine Delivery Agency (SDA), with the vehicle designed and built by Plymouth-based company MSubs. The resulting vessel was launched in February 2025 and formally named Experimental Vessel (XV) Excalibur in May 2025. Ownership passed to the Royal Navy in December 2025, and the vessel is operated as an experimental platform within the Fleet Experimentation Squadron.
Specifications
| Type | Submarine |
| Manufacturer | MSubs, Plymouth |
| Status | In service |
| Length | 12 m |
| Displacement | 19 t |
| Main armament | None |
Operators
| Country | Quantity | Confidence |
|---|---|---|
| United Kingdom | — | confirmed |
Text adapted from Wikipedia, available under CC BY-SA 4.0. Photo from Wikimedia Commons; see the Wikipedia article for author and license.
