BAE Systems recently conducted a two-week operational demonstration of the Herne XLAUV off the south coast of England, showcasing its capabilities in intelligence, surveillance, and reconnaissance (ISR) missions. Developed in collaboration with Cellula Robotics, Herne is designed to meet the emerging demand for an attritable XLAUV capable of diverse missions such as anti-submarine warfare (ASW), electronic warfare (EW), and protection of critical national infrastructure (CNI). The demonstration involved representatives from 10 nations, including NATO and Five Eyes partners, observing the ISR mission vignette. Herne integrates Cellula Robotics' Solus-XR AUV, BAE Systems' Nautomate control software, and mission-specific plug-ins for payload integration, delivering system-level assurance for military applications. The vehicle's modular design allows for quick payload reconfiguration and provides up to 5,000 liters of payload space. During the demonstration, Herne showcased its capabilities in covert sub-surface entry, autonomous navigation, and ISR data collection and sharing. The vehicle is currently configured with Lithium-ion batteries but is being considered for integration with hydrogen fuel cell technology for extended endurance. BAE Systems plans to continue development on the Herne XLAUV, including enhancing the Nautomate control software, implementing additional mission-based plug-ins, and evaluating aspects like launch and recovery operations. The company also aims to offer an operational battle-ready configuration of the Herne XLAUV by mid-2026, with the potential inclusion of hydrogen fuel cells to meet future naval requirements efficiently and cost-effectively.