The United Kingdom has begun testing a new fleet of underwater drones designed to track Russian spy ships operating near British shores, in what officials describe as a crucial step toward strengthening national security and protecting critical undersea infrastructure.
The drones—known as SG Fathom underwater gliders—function like remotely piloted torpedoes. They can patrol silently beneath the surface for several days, gathering intelligence and monitoring suspicious activity in deep waters.
According to Katie Raine, the Fathom program lead, the drones are capable of scanning vast underwater areas and detecting potential threats significantly faster than traditional monitoring systems. She told the BBC that this new technology represents a “major leap” in maritime surveillance.
If current tests succeed, the Fathom drones will be integrated into Atlantic Bastion, the UK’s expanding security network that combines drones, Royal Navy vessels, and surveillance aircraft to protect undersea pipelines, communication cables, and other essential infrastructure.
The British Ministry of Defence has confirmed a 30% increase in Russian underwater activity over the past two years, with a growing number of vessels probing or approaching UK territorial waters. The Kremlin’s operations have raised alarms across Europe, especially following last month’s incident involving the Russian vessel Yantar, whose crew reportedly used a laser to interfere with RAF pilots observing the ship.
UK defence officials emphasize that the new strategy is not only aimed at strengthening fleet protection but also at securing underwater infrastructure that powers global communication and energy flows—assets increasingly vulnerable to Russian hybrid warfare tactics.
