A Russian submarine was shadowed through UK waters by the Royal Navy during a powerful storm, in what officials described as a tightly coordinated three day tracking operation that underscores heightened tensions over undersea security.
Dramatic images showed the stealthy Kilo class submarine Krasnodar moving through the English Channel, closely monitored by British forces. The Soviet era vessel, accompanied by its tugboat Altay, traveled from the North Sea, passed through the Strait of Dover, and entered the English Channel under constant surveillance.
The Royal Fleet Auxiliary (RFA) support ship Tidesurge, carrying a Merlin helicopter for airborne surveillance, followed the submarine throughout its journey. Captain James Allen, commanding officer of RFA Tidesurge, said there is nothing like a Russian submarine to focus the mind for any mariner.
Lieutenant Commander David Emery, flight commander of 814 Naval Air Squadron’s Atlantic Flight, added that maintaining an overt presence and continued overwatch of Russian vessels in UK waters is vital for national security.
Despite rough weather sweeping across the UK, the submarine sailed on the surface until it reached waters near the island of Ushant, off northwest France, where monitoring responsibilities were handed over to a NATO partner. The operation lasted three days and required close coordination between the RFA, naval aviation units, and allied forces.
The Merlin helicopter, based at Royal Naval Air Station Culdrose in Cornwall, remained embarked on RFA Tidesurge throughout the operation. Expert aircrew were prepared to pivot to anti submarine operations if Krasnodar had dived below the surface, though the vessel remained surfaced despite stormy conditions.
The Kilo class submarine is known for its stealth capabilities and has been dubbed Black Hole by some in the US Navy due to its ability to operate quietly underwater. Designed in the 1970s by the Soviet Union, these submarines remain a key part of Russia’s naval force, equipped with torpedoes, naval mines, and Kalibr cruise missiles capable of long range strikes.
Thursday’s operation follows a similar incident in July 2025, when Portsmouth based patrol ship HMS Mersey, a Wildcat helicopter, and a submarine hunting Merlin aircraft tracked another Russian submarine, Novorossiysk, as it passed through UK waters. The Royal Navy said Russian vessels threatening UK waters have increased by 30 percent over the past two years.
Earlier this week, Defence Secretary John Healey unveiled plans to protect critical undersea cables and pipelines from Russian submarine activity through a new programme called Atlantic Bastion. The Ministry of Defence said the initiative was in direct response to the resurgence in Russian submarine and underwater activity.
Atlantic Bastion will combine ships, submarines, aircraft, and unmanned vessels connected through artificial intelligence (AI) powered acoustic detection technology and integrated into a digital targeting web. The programme represents a pioneering network of weapons systems that allow battlefield decisions for targeting enemy threats to be made and executed faster.
The initiative places the UK at the forefront of a technological revolution in naval warfare, combining the latest autonomous surface and underwater vessels and cutting edge digital infrastructure with world class warships and patrol aircraft. It will create an advanced hybrid naval force to defend the UK and NATO allies against evolving threats.
Combined Ministry of Defence and industry investment of £14 million has already been committed this year to testing and development. Twenty six firms from the UK and Europe have submitted proposals to develop anti submarine sensor technology, and 20 companies are already showcasing technology demonstrators.
During a visit to Portsmouth Naval Base on 8 December 2025, Healey warned that Russian activities pose a significant threat to critical infrastructure. “We track what their ships do. We track what their submarines are doing. We know that they are mapping our undersea cables and our networks and our pipelines, and we know that they are developing new capabilities all the time to put those at risk,” he said.
UK Defence Intelligence has identified that Russian President Vladimir Putin is currently modernizing his fleet to target critical undersea cables and pipelines. The Royal Navy has repeatedly tracked Russian spy ship Yantar around UK waters, with the vessel observed near sensitive infrastructure.
Atlantic Bastion will see capabilities deployed in the water next year, with further investment to accelerate and expand the programme to follow. The initiative will enable the UK to find, track, and if required, act against adversaries with unprecedented effectiveness across vast areas of ocean.
Subsea infrastructure carries 99 percent of international telecommunications data and vital energy supplies including electricity, oil, and gas. The move comes after cables in the Baltic Sea were reported damaged recently, raising concerns about potential sabotage operations.
The UK and Norway also recently signed the Lunna House defence pact to strengthen protection of vital undersea cables. In September 2025, the parliamentary National Security Committee warned that Britain was not confident in its ability to defend its submarine cable network, adding that a successful attack would cause catastrophic disruption.
First Sea Lord General Sir Gwyn Jenkins, speaking at the International Sea Power Conference in London on 8 December, set out his vision for the future of the Royal Navy. “We are a Navy that thrives when it is allowed to adapt. To evolve. We have never stood still because the threats never do,” he said.
Jenkins described Atlantic Bastion as a bold new approach to secure the underwater battlespace against a modernizing Russia. “A revolutionary underwater network is taking shape from the Mid Atlantic Ridge to the Norwegian Sea. More autonomous, more resilient, more lethal, and British built,” he stated.
The programme forms part of a broader Warfighting Ready Plan 2029 under development, which also includes Atlantic Shield focusing on air defense and Atlantic Strike emphasizing deterrence capabilities. The Strategic Defence Review identified the maritime domain as increasingly vulnerable and maritime security as a strategic imperative for the UK.
NATO Secretary General Mark Rutte warned alliance members on the same day to get serious about the growing threat from Russia. Speaking in Berlin, he said the slow pace of military investment by too many allies was deeply concerning. “We are Russia’s next target. I fear that too many are quietly complacent. Too many don’t feel the urgency. And too many believe that time is on our side. It is not. The time for action is now,” Rutte stated.
