UK Prepares to Tackle Russian Shadow Fleet Ships in UK waters

The UK has revealed it is ready to act against Russian ‘shadow fleet’ shipping sailing in UK waters, including boarding and detaining ships if required. According to a BBC report, approval for this military activity was given by the UK Prime Minister, Sir Kier Starmer, on 26 March. Broadly, Russia’s ‘shadow fleet’ consists of commercial ships sailing without a valid national flag and transporting Russian oil, despite international sanctions imposed on some Russian trade exports including oil, as a consequence of its invasion of Ukraine. Export of such oil could help fund its war there. Speaking on BBC Radio 4’s Today programme on 26 March, UK Secretary of State for Defence John Healey explained that authorisation followed a process of legal, military, and other preparations (including discussions with allies). “What operations like this require is training, preparation, understanding discussion with allies, [and] a clear legal basis, like every military action we take: that legal basis [and] the military options are now lined up and ready,” said Healey. “It’s a signal that we will take action.” Being ready and prepared to tackle ‘shadow fleet’ ships may be sending a wider deterrence signal to Russia, too. “We have seen Russian oil revenues fall by one quarter [since October 2024], but particularly now when [Russian president Vladimir] Putin may want to take advantage of a distraction of the Middle Eastern conflict and the rising oil price, we’re ready with allies to do more,” Healey continued. “This is a signal to Putin that he may want us to be distracted by the Middle East, but we’re ready to act.” The UK’s commitment to its North Atlantic deterrence and defence responsibilities was reiterated earlier this month, when the government confirmed the HMS Prince of Wales carrier strike group would continue with a planned deployment to the High North on a NATO tasking, rather than responding to some political clamour to send the carrier to the Eastern Mediterranean, or further afield, in response to the current Gulf crisis. Underlining the importance of working with allies on the ‘shadow fleet’ issue, the UK has already supported French and US boarding activities. According to the BBC, it has also worked with other countries in monitoring and tracking ‘shadow fleet’ ships, including Estonia, Finland, and Sweden. For the UK, preparations for its own operations will have involved training specialist units to conduct interceptions, including dealing with unco-operative crews, plus also being aware of the potential presence of Russian naval vessels, which have been used to escort ‘shadow fleet’ shipping in recent months, including in the North Sea. The UK has several options across its naval service, including Royal Marines Commandos and Special Boat Service personnel, offering the specialist capabilities, experience, skills, and training to conduct vessel board, search, and seize (VBSS) operations. As regards working with allies, the UK will be sharing ship-tracking tips and technology tools with countries around the English Channel and North and Baltic seas. Ship-tracking technologies, including automatic identification system (AIS), are crucial for ship identification. Moreover, the UK is working very closely on the ‘shadow fleet’ matter with the Joint Expeditionary Force (JEF). A UK-led, 10-country, high-readiness military construct focused geographically on the North Atlantic and politico-militarily on building deterrence and defence at a sub-conflict-threshold level, JEF has been developing significant maritime presence to counter asymmetric threats including securing critical undersea infrastructure (CUI) and addressing the ‘shadow fleet’ risk. For example, in January 2025, JEF countries activated an advanced, artificial intelligence (AI)-based tracking system called ‘Nordic Warden’ to monitor both ‘shadow fleet’ ships and suspicious shipping activity around CUI nodes. The system integrates AI with data sources like AIS, collects data relating to ships of interest so they can be monitored, and sends alerts if needed. In January 2026, Healey had said the UK was “stepping up action on the ‘shadow fleet’, developing further military options and strengthening co-ordination with allies”. A key step taken was identifying a legal framework within which military forces could conduct permissible enforcement activities against ships believed not to be flying a legitimate flag. According to the BBC, the 2018 Sanctions and Money Laundering Act provides this framework. In February, JEF representatives convened at the Munich Security Conference to discuss military options for addressing the ‘shadow fleet’ issue. In mid-March, they met again to consider the legal framework for military operations, within efforts to build strategic understanding of the legal basis for countering ‘shadow fleet’ activity in accordance with international law (a UK government statement said). At this time, the UK government noted it had imposed sanctions on 544 suspected ‘shadow fleet’ ships. On 26 March, following a meeting in Helsinki, Finland, JEF announced that, in the context of increasing deterrence activity against sub-conflict-threshold threats, its member states will collaborate more closely on the ‘shadow fleet’ risk within wider JEF efforts to counter the military element of asymmetric activities, including through building best practice and common approaches. Naval News comment Geostrategically, the ‘shadow fleet’ issue will be an important one for NATO North and Baltic sea countries. In the absence of secured maritime access from the Eastern Mediterranean/Black Sea region (after Türkiye closed the Bosporus/Dardanelles straits following the Ukraine war breaking out, and with the 2024 fall of Syria’s Assad regime removing Russian access to the port of Tartus), maritime access from Kaliningrad and St Petersburg into the Baltic and North seas and beyond is significantly more important to Russia. Thus, given the impact of sanctions upon Russian exports, ‘shadow fleet’ shipping activity is likely to be more significant in this region – hence the escort presence of Russian naval ships alongside ‘shadow fleet’ shipping.