The British Ministry of Defence has reportedly uncovered a covert Russian operation involving the placement of underwater surveillance sensors in UK territorial waters. These devices are believed to have been monitoring the movements of the Royal Navy’s Vanguard-class nuclear submarines — the backbone of the United Kingdom’s nuclear deterrent.
The sensors were found near areas used by the Royal Navy for submarine operations and are thought to be capable of detecting acoustic signatures, enabling foreign actors to track the submarines’ locations. The discovery has prompted renewed concern over Russia’s increasing use of “gray zone” tactics — aggressive but non-declared acts of warfare that avoid open conflict.
British defense sources suggest that the surveillance network may have been installed well before Russia’s full-scale invasion of Ukraine in 2022. Intelligence reports indicate that Russian-owned luxury yachts — some equipped with moon pools and advanced sonar — may have been involved in deploying the underwater technology discreetly along the British coastline.
The Royal Fleet Auxiliary vessel Proteus, specially commissioned for undersea surveillance, has been active in counter-sensor operations and protecting critical underwater infrastructure. The UK has invested heavily in such vessels to safeguard against potential tampering with fiber-optic internet cables, offshore energy systems, and defense networks.
Concerns over undersea sabotage have grown across NATO in recent years. Several subsea internet cables in the Baltic and North Seas have been mysteriously severed or damaged — often in areas near known Russian naval activity. Britain, alongside its allies, is ramping up efforts to monitor suspicious maritime movements and ensure that its deterrent submarines continue to operate unseen, as they have for over 50 years.
The Ministry of Defence has not publicly commented on the exact locations of the sensor findings but emphasized that the UK “will not tolerate” hostile intelligence-gathering operations in its waters.
