The United Kingdom has conducted a significant test by launching a U.S. torpedo from an uncrewed underwater vessel for the first time. This event marks a major step forward in enhancing NATO’s naval capabilities and Euro-Atlantic security. The test follows recent comments by General Sir Gwyn Jenkins, the U.K.’s First Sea Lord, emphasizing the need for more warships and drones to safeguard the Atlantic. Jenkins highlighted the growing threat from Russia, which boasts advanced submarines equipped with long-range precision weapons and deep-water systems.

The Ministry of Defence (MOD) announced that the U.K. fired a heavyweight torpedo using the British-made XV Excalibur, a 40-foot-long undersea drone. This launch represents the first time that either the U.K. or the U.S. has achieved such a feat with an uncrewed vessel and demonstrates the technological collaboration within the AUKUS alliance, which includes the U.K., U.S., and Australia.

Details on XV Excalibur

While specific details about the trial’s location and timing remain undisclosed, U.K. Minister of State for Defence Luke Pollard mentioned on LBC radio that it occurred at a testing range off Scotland’s north coast. Observations from Navy Lookout suggest that the trial may have taken place at the British Underwater Test and Evaluation Centre.

Pollard described the test as a crucial step toward integrating crewed and uncrewed vessels, enhancing the North Atlantic’s security against threats like Russia. Last December, the MOD categorized Excalibur as an Extra-Large Uncrewed Underwater Vehicle (XLUUV) developed under the Royal Navy’s Project Cetus by Plymouth-based MSubs and the UK’s Submarine Delivery Agency. Excalibur is a 12-meter experimental vessel with a 19-ton displacement, making it the largest uncrewed underwater vessel tested by the Royal Navy. It was unveiled in May 2025, with ongoing sea trials planned over two years.

In a notable collaboration, the U.K. and Australia conducted a joint trial of Excalibur in 2025 as part of Exercise Talisman Sabre. During this, operators in Australia remotely controlled the vessel, underscoring the system’s interoperability between the two nations. Navy Lookout noted that while Excalibur lacks torpedo tubes, a large central payload bay allows for firing torpedoes. The Mk 48 torpedo, used in recent trials, required a cradle attachment for deployment from the hull.

Understanding AUKUS

The recent Excalibur trial showcases progress within AUKUS, a trilateral defense partnership between Australia, the U.K., and the U.S. Announced in September 2021, AUKUS addresses strategic challenges in the Indo-Pacific, particularly from China. Pillar 1 of AUKUS involves Australia’s acquisition of nuclear-powered attack submarines and the presence of U.S. and U.K. submarines in Australia. Pillar 2 focuses on enhancing undersea capabilities and technological collaborations like AI and electronic warfare. Unveiled in May this year, the first Pillar II project aims to develop payloads for uncrewed undersea vehicles.