Plymouth warships help expose Russian 'covert' sub operation

PLYMOUTH-based frigates HMS St Albans and HMS Somerset have been at the forefront of a major British military operation to intercept and expose a “covert” Russian naval mission in UK waters.

In a statement released today, 9 April 2026, the Ministry of Defence (MoD) confirmed that the Royal Navy has spent several weeks tracking a Russian attack submarine and specialised vessels targeting critical undersea infrastructure.

The operation began when an Akula-class Russian attack submarine entered international waters in the High North. However, British intelligence quickly established that the submarine was acting as a distraction.

While the Akula drew attention, specialist units from Russia’s Main Directorate of Deep Sea Research (known as GUGI) were identified conducting “nefarious activity” near critical undersea fibre optic cables and pipelines. These subsea cables are essential for over 99 per cent of the UK’s international data traffic and global banking.

Two Plymouth-based Type 23 frigates were central to the response:

HMS St Albans: Deployed alongside RFA Tidespring and Merlin helicopters to track the Akula-class submarine 24/7. The crew covered thousands of miles and used sonobuoys to maintain a constant lock on the vessel.

HMS Somerset: Conducted a separate 10-day intensive monitoring operation in the English Channel and North Sea, shadowing a Russian fleet that included a destroyer, a frigate, and a Kilo-class submarine.

The MoD confirmed that once the UK and its allies (including Norway) began “overt” tracking to signal the Russians were no longer hidden, both the GUGI units and the attack submarine abandoned their operation and retreated back toward Russia.

Defence Secretary John Healey, speaking from Downing Street, warned that Russian activity around the UK has increased by 30 per cent over the last two years.

“To Putin, I say this: we see you, we see your activity over our underwater infrastructure. You should know that any attempt to damage it will not be tolerated and would have serious consequences,” Mr Healey said.

Prime Minister Keir Starmer emphasised that the operation was crucial to protecting the British public from the economic impact of infrastructure sabotage.

The government has now pledged an additional £100 million to support P-8 submarine-hunting aircraft and is investing in the “Atlantic Bastion” programme. This project will combine autonomous systems with the Royal Navy’s existing fleet of warships to bolster the protection of the UK’s undersea interests.

While the Russian vessels involved in this specific operation have retreated, the Royal Navy remains ready to respond should they return to British waters.