The United Kingdom’s recently unveiled Defence Investment Plan (DIP) places a significant emphasis on unmanned systems, particularly maritime drones and autonomous submarines, as central to the future of the country’s military strategy. The plan, announced in early July 2026, reflects growing concerns over Russian activities in the Atlantic, specifically efforts to map and potentially threaten Britain’s underwater cables and pipelines.

A key shift in the plan involves the cancellation of eight planned Type 83 destroyers—ships originally intended for air defence—and their replacement with a smaller fleet of at least six common combat vessels (CCVs). These CCVs are envisioned not only as crewed warships but also as “motherships” for a range of unmanned platforms operating in the air, on the surface, and beneath the sea. General Sir Gwyn Jenkins, First Sea Lord and head of the Royal Navy, described the envisioned force as a “hybrid navy” where human-crewed ships coordinate closely with drones and other advanced weapon systems to enhance operational capacity, survivability, and firepower.

However, the CCVs are still in the conceptual stage, with no designs finalized, prompting skepticism within naval circles about whether the new approach will deliver as promised. Critics have pointed to the limited technical details in the DIP, especially regarding the new unmanned vessel types, which include a missile-launch platform (Type 91), an anti-submarine sensor ship (Type 92), an uncrewed submarine (Type 93), and a radar ship (Type 94). Concerns persist about timely and on-budget delivery of these cutting-edge systems, given their experimental nature.

Among the companies advancing autonomous maritime technology is Anduril, a U.S.-based defense firm with a UK presence. Anduril’s Seabed Sentry—a weighted, sensor-laden cylindrical device capable of monitoring underwater activity—is designed to be deployed en masse by autonomous submarines. When placed on the seabed, these devices form a network that can detect and relay information about potential threats or espionage activity beneath the waves. Richard Drake, managing director of Anduril UK, highlighted the advantage of deploying multiple smaller, cheaper assets compared to relying solely on crewed frigates or submarines, which are fewer and more costly to operate.

The deployment of autonomous platforms aims to address current gaps in the monitoring of critical underwater infrastructure, which remains resource-intensive and uneven. By leveraging artificial intelligence and networks of small devices, the UK hopes to extend its surveillance capabilities across a wider area with fewer personnel. Anduril’s portfolio also includes an autonomous underwater vehicle (AUV) already in service with the Royal Australian Navy, as well as an autonomous attack torpedo known as Copperhead, which can be launched from their AUV.

Experts like Matthew Savill from the Royal United Services Institute acknowledge that the emphasis on autonomy fits into a broader strategy to compensate for the smaller scale of Britain’s armed forces. However, he warns that this “bold bet” on technological innovation leaves little room for setbacks, underscoring the need for rapid procurement and implementation to ensure the plan’s success.

As the UK moves forward with its defence modernization, the integration of autonomous systems alongside traditional naval assets represents an attempt to balance limited resources with emerging threats, particularly in the contested undersea domain. Whether this hybrid approach will achieve its strategic goals remains to be seen amid ongoing debates over feasibility and timelines.