Exclusive Report: British Navy conducts remote intelligence mission with undersea robot XLUUV Excalibur over 16,000 km.

According to information released by the British Royal Navy, a landmark undersea trial has confirmed the United Kingdom’s ability to conduct a real-time intelligence mission using its new autonomous submarine Excalibur, while controlling the system remotely from over 16,000 km away. The operation took place during the most recent edition of Exercise Talisman Sabre, where British Royal Navy personnel stationed in Australia directed the Excalibur XLUUV as it carried out a submerged mission in UK waters.
Follow Army Recognition on Google News at this link

Excalibur, the British Royal Navy’s first Extra Large Uncrewed Underwater Vehicle (XLUUV), during trials off the UK coast. The 12-meter autonomous submarine is designed for long-range intelligence, surveillance, and undersea operations, with no crew on board. (Picture source: UK MoD)

This represents the first successful demonstration of an uncrewed submarine being remotely operated across intercontinental distances, marking a major technological milestone in the integration of autonomous systems within the AUKUS alliance.

Excalibur is the British Royal Navy’s first Extra Large Uncrewed Underwater Vehicle, designed to operate independently for extended durations, perform high-risk missions without human presence, and deliver persistent undersea capabilities. Measuring 12 meters in length and weighing nearly 19 tonnes, the platform was developed under the Cetus program by MSubs, a specialist UK-based defense contractor. Excalibur is constructed with a modular, open-architecture framework that allows rapid payload reconfiguration based on mission requirements. It features a suite of advanced acoustic sensors, bathymetric mapping tools, and encrypted communications links, allowing operators to adjust or retask the vehicle while it remains submerged.

Unlike traditional submarines, Excalibur can be launched, tasked, and recovered without a crew onboard, significantly reducing operational risk in contested or denied environments. The vehicle is engineered for missions such as seabed surveillance, undersea cable monitoring, maritime domain awareness, and detection of hostile underwater activity. Its quiet electric propulsion system and low acoustic signature make it an ideal platform for covert intelligence collection. This trial confirms that Excalibur can receive commands from globally distributed control nodes and continue executing complex missions autonomously with minimal human input.

The trial was conducted under the AUKUS Pillar II framework, which focuses on the rapid development and deployment of advanced defense technologies beyond the scope of the nuclear submarine program under Pillar I. Maritime Big Play, one of Pillar II’s key initiatives, aims to test and integrate robotic and autonomous systems for use across the AUKUS nations. The operation with Excalibur was not just a technical experiment. It was a real-world demonstration of remote undersea warfare capability, proving that AUKUS partners can project underwater power globally with accuracy, coordination, and speed.

Captain Keith Taylor, British Royal Navy Senior Responsible Owner for Maritime Big Play, stated that the exercise marked the transformation of experimental platforms into tools ready for frontline use. Commodore Marcus Rose, Deputy Director of Underwater Battlespace, described the operation as a decisive advancement in the British Royal Navy’s ability to integrate uncrewed systems into joint operations with Australia. This reinforces the British Royal Navy’s growing contribution to collective deterrence across the Indo-Pacific and Euro-Atlantic theaters.

In parallel, Japan participated in the exercise to strengthen its role in underwater acoustic communications and increase coordination with AUKUS uncrewed systems. Since joining Pillar II cooperation in late 2024, Japan has been working closely with partner nations on maritime autonomy and cyber-resilient technologies. During the exercise, Japanese units contributed to data-sharing and interoperability trials that aimed to fuse robotic assets into a common underwater picture.

This demonstration sends a clear strategic signal. As adversaries expand their undersea presence with advanced and stealthy platforms, the ability to control an autonomous submarine from another continent offers unmatched flexibility and strategic depth. Excalibur provides the British Royal Navy and its allies with a cost-effective, persistent solution for undersea surveillance and seabed operations, without the vulnerabilities of manned systems or forward-deployed bases.

The success of Excalibur’s long-distance operation confirms a new direction in undersea warfare. Autonomous platforms integrated with satellite communications and advanced control systems now offer real-time, cross-theater capabilities. The British Royal Navy’s investment in Excalibur places the United Kingdom at the forefront of this shift, positioning its naval forces as leaders in the next generation of maritime power projection.