The British announcement that Russian ships from the so-called shadow fleet could be stopped and boarded in British waters in the event of sanctions violations has so far had little apparent deterrent effect.
According to a Reuters analysis of ship data, at least 25 sanctioned vessels have sailed through British waters in the English Channel area since the government’s declaration. No boarding operations have been reported to date.
Prime Minister Keir Starmer announced the measure on 25 March. The British government stated that the armed forces could stop and search shadow fleet vessels in national waters and detain them in the event of violations. London justified the move as an effort to increase pressure on Russia’s oil exports and thus its war financing. According to the government, the UK and its partners have sanctioned 544 ships linked to the shadow fleet.
Bureaucracy hinders rapid enforcement
In practice, however, implementation remains difficult. According to Reuters, the British Ministry of Defence said that potential measures would be assessed on a case-by-case basis. Experts also point to complex legal constraints. International law expert Douglas Guilfoyle told Reuters that there is only a very limited and legally unresolved basis for detention in the absence of a corresponding UN sanctions regime.
There are also operational and political risks. According to Reuters, former British naval officer James Fennell assumes that London will first test the impact of the public threat before taking potentially risky action at sea. For this reason, the British approach should initially be seen primarily as a deterrent and political signal.
The English Channel remains a key route for shadow fleet vessels operating between the Baltic Sea, north-western Europe and more southerly shipping areas. According to data company Pole Star Global, an average of around 25 such ships transit British waters each week. The fact that traffic has not declined noticeably despite tougher rhetoric highlights the limits of unilateral national action.
France sentences captain of shadow fleet tanker
Meanwhile, a French court in Brest has sentenced the captain of the 244-metre tanker “Boracay”, which is linked to the shadow fleet, in absentia to one year in prison and a fine of €150,000.
According to the judiciary, he allegedly ignored instructions from the French navy when the EU-sanctioned vessel was stopped off the coast of Brittany at the end of September 2025. In addition to the proceedings, the tanker is also suspected of links to drone incidents in Denmark.
