The Royal Navy has demonstrated for the first time that its new Experimental Vessel (XV) Excalibur can be controlled from the other side of the world, with operators in Australia directing the uncrewed submarine while it was submerged in UK waters, UK Defence Journal reports.
The test, carried out in July during Exercise Talisman Sabre 2025’s “Maritime Big Play” series, was part of the AUKUS Pillar II programme to develop and share advanced technologies, according to a Royal Navy news release.
The 12-metre Excalibur is the Royal Navy’s first Extra Large Uncrewed Underwater Vehicle (XLUUV), unveiled earlier this year after a three-year development project known as Cetus.
Control of the UK vessel from a remote operating centre in Australia, more than 10,000 miles from its home at HMNB Devonport in Plymouth, marked what the Navy described as a milestone in uncrewed system interoperability. According to Commodore Marcus Rose, RN, Deputy Director Underwater Battlespace, “The XLUUV exercise was a big step forward in our ability to operate uncrewed systems interchangeably with Australia.”
The exercise also saw the UK, Australia, and the United States working with Japan to advance underwater acoustic communications. It follows AUKUS partners’ decision in 2024 to explore interoperability with Japan’s maritime autonomous systems as a first step in Pillar II collaboration.
Captain Keith Taylor, RN, the UK Senior Responsible Owner for Maritime Big Play, said in the release, “This exercise demonstrates how we are exploiting the learning from our experimentation, by applying it to the Royal Navy’s growing arsenal of Uncrewed Underwater Vehicles; taking experimentation into the hands of the war fighter.”
Maritime Big Play is a series of joint experiments aimed at integrating robotics and autonomous systems into naval operations. Building on last year’s events, the 2025 iteration placed greater emphasis on command-and-control across vast distances and in contested environments.
