IN Brief:
- BAE Systems is preparing trials of an updated Herne extra-large autonomous underwater vehicle.
- The new version is expected to enter the water in 2026, with trials planned in Canada in 2027.
- The redesign points toward easier manufacture, modular payload integration, underwater ISR, and future naval autonomy production.
BAE Systems is preparing an updated Herne extra-large autonomous underwater vehicle for trials, moving the programme toward a configuration shaped by manufacture, modularity, and naval support as much as in-water performance.
The new version is expected to enter the water in 2026, with trials planned in Canada in 2027. It follows the Herne Alpha demonstrator developed with Canadian company Cellula Robotics and tested in 2024. BAE Systems will design the updated vehicle, while Cellula Robotics will manufacture it, creating a practical UK-Canadian industrial route into extra-large uncrewed underwater systems.
Herne is aimed at a naval requirement that has become more urgent as undersea infrastructure, seabed warfare, and anti-submarine activity have moved higher on defence agendas. Extra-large autonomous underwater vehicles can support intelligence, surveillance, reconnaissance, seabed monitoring, payload delivery, mine countermeasure activity, and other missions where crewed submarines are scarce, expensive, or unnecessarily exposed.
The updated design’s manufacturing approach is one of its more important features. A move toward a bolted aluminium framework suggests an effort to simplify fabrication, maintenance, and modification. Underwater autonomy cannot scale if every vehicle is effectively a bespoke engineering artefact. Navies need repeatable builds, accessible modules, repairable structures, and documented interfaces that allow payloads to change without redesigning the whole vehicle.
Aluminium construction brings practical advantages and engineering trade-offs. It can support faster fabrication, manageable cost, and easier access for maintainers, but underwater vehicles still face corrosion, pressure, sealing, fatigue, and acoustic requirements. Bolted structures must preserve watertight integrity and survivability while allowing technicians to reach internal systems. The useful balance is a design that is easier to build without becoming fragile in service.
Modularity will define the vehicle’s long-term value. An XLAUV needs space, power, data, cooling, and mechanical interfaces for different payloads, including sonar, ISR masts, environmental sensors, communications systems, electronic payloads, mission modules, and future equipment. Payload flexibility only works when interfaces are disciplined. A spacious bay without controlled standards can quickly become another bespoke integration problem.
Underwater autonomy imposes constraints that air and surface drones do not face in the same way. Radio communication is limited beneath the surface, acoustic links carry less data, and surfacing can compromise the mission. The vehicle must navigate accurately, follow mission plans, manage contingencies, and return safely with limited real-time instruction. Autonomy, navigation, energy management, and fault handling therefore become core production requirements.
Energy systems will be central to endurance and supportability. Batteries, charging equipment, thermal management, safety procedures, transport arrangements, and maintenance cycles all affect how often a vehicle can be deployed. A long-range vehicle that takes too long to prepare, inspect, charge, or repair will lose operational usefulness. Production design has to account for turnaround and support, not only maximum range.
The support model will be demanding. A deployable XLAUV requires pressure housings, propulsion, control surfaces, navigation systems, mission computers, sonar, payload interfaces, transport frames, launch and recovery equipment, secure software loading, and test procedures. Each part needs suppliers, documentation, quality assurance, and configuration control. As with surface autonomy moving into production, the vehicle is only part of the capability.
Canada’s role gives the programme an additional industrial route. Cellula Robotics brings underwater robotics and manufacturing experience, while Canadian trial activity offers demanding maritime conditions for development. For BAE Systems, the collaboration supports a model in which design authority and specialist manufacturing are shared across allied industry rather than held inside one national facility.
Fleet adoption will require more than successful trials. Navies must determine how XLAUVs are transported, launched, recovered, commanded, maintained, and integrated with submarines, surface ships, maritime patrol aircraft, and shore-based command systems. Safety and legal frameworks must also catch up with vehicles operating autonomously below the surface. The technology may mature faster than the doctrine around it.
Herne’s updated configuration suggests a programme leaving the early demonstration phase behind. The next stage will test whether an XLAUV can be built, modified, trialled, and supported repeatedly without becoming a one-off engineering exercise. Underwater autonomy will be judged by endurance and stealth, but it will be delivered through structures, payload bays, energy systems, interfaces, software baselines, and production discipline.
