The UK’s Anti-Submarine Warfare (ASW) Spearhead program is driving the adoption of autonomous tech in maritime defense. By bringing together the Royal Navy, industry partners, and research organizations, the initiative has quickly moved from concept to operational platforms.
The program has delivered three autonomous naval testbeds — CETUS, PROTEUS, and SCYLLA — each designed to enhance the country’s undersea and aerial operations while reducing reliance on crewed systems.
CETUS
CETUS, a 12-meter (39-foot), 20-tonne (55,100-pound) autonomous underwater vehicle, is Britain’s largest uncrewed submarine to date.
Developed with Plymouth-based MSubs, the platform costs 15.4 million pounds ($19 million) and was delivered in late 2022. It began sea trials in February 2025.
Renamed XV Excalibur in May, CETUS carries a large payload bay for anti-submarine warfare, seabed operations, and intelligence gathering.
PROTEUS
PROTEUS, a 3-tonne (6,600-pound) autonomous rotary platform built by Leonardo, moved from initial requirements to actual hardware in just three years.
It is currently exploring autonomy and mission modularity through sonobuoy drops and communications relay, to reduce the need for crewed flights.
Future missions could include logistics support, maritime surveillance, and search-and-rescue coordination.
SCYLLA
SCYLLA advances submarine-launched autonomy with a torpedo-tube launch-and-recovery system and a modular midsection for mission-specific payload.
The platform will support AUKUS Pillar 2 objectives, including seabed warfare, intelligence operations, and covert surveillance missions.
It is now undergoing trials on Astute-class submarines, with initial operating capability expected between 2026 and 2027.
Securing Britain’s Naval Future
The three platforms are built to expand the Royal Navy’s autonomous naval capabilities while reducing operational risks and lifecycle costs.
Officials said the ASW Spearhead program demonstrates how streamlined governance and collaboration can speed up the development and deployment of military technology.
It also supports the UK’s broader AUKUS objectives.
