In a report published on Friday, the conflict-monitoring organisation ACLED describes an increasingly emboldened maritime system that allows Moscow not only to circumvent sanctions, but to operate in the grey area between commerce, espionage, intimidation and sabotage.

Despite hundreds of sanctions, Russia is still successfully using the fleet to sustain its war economy, exposing vulnerabilities in Europes critical infrastructure.

According toACLED, the fleet comprises anywhere between 1,000 and 3,200 vessels. Ukrainian authorities have identified nearly 1,400 ships, while estimates suggest the network now transports up to 80 percent of Russias seaborne crude exports.

Many of the vessels are ageing tankers hidden behind layers of shell companies, false registrations and frequent name changes.

Crews are reportedly recruited through WhatsApp, communications rely on Starlink, payments can be made in cryptocurrency, and ships often manipulate or disable theirAutomatic Identification Systemsto avoid tracking.

This has allowed Moscow to keep oil moving around the globe even as the European Union, the United Kingdom and the United States have imposed broad sanctions. As of May 2026, the EU alone had sanctioned 632 vessels linked to the shadow fleet.

However, under theUN Convention on the Law of the Sea, European states cannot board or seize suspicious vessels unless they can prove criminal activity or demonstrate that a ship is effectively stateless which has created an ideal operating environment for Russia.

The Baltic Sea's critical European infrastructure

Dark vessels: how Russia steers clear of Western sanctions with a shadow fleet

Military implications

The Baltic Sea has become the focal point of shadow fleet activity, being home toRussias major oil terminalsat Primorsk and Ust-Luga. The region is also dense with undersea telecoms cables, electricity links and gas pipelines connecting Nordic and Baltic states.

OnNew Years Eve 2025, Finnish special forces boarded the cargo ship Fitburg after an undersea cable between Helsinki and Tallinn was damaged. Investigators said the vessel had dragged its anchor along the seabed while travelling from St Petersburg towards Israel. Finnish authorities later discovered sanctioned Russian steel on board.

Although investigators stopped short of claiming deliberate sabotage, the episode highlighted the increasingly blurred line between sanctions evasion and hybrid warfare.

Maritime intelligence companyWindwardrecorded more than 2,300 Russian-affiliated vessels entering the Baltic between February 2024 and February 2025. During the same period,drifting activitywhen a vessel is stationary or moving slowly without any obvious navigational purpose near subsea infrastructure increased dramatically, while more than 16,000 gaps in vessel tracking signals were recorded.

The result is a persistent atmosphere of uncertainty that benefits Moscow, according to Windward.

Drone incident near French carrier in Sweden points to possible Russian link

French enforcement

France has become one of the more visible European players in terms of testing how far coastal states can go in response to Russias shadow fleet.

One key case involved the tanker Pushpaalso known as theKiwala or theBoracaya sanctioned vessel operating on the Russia to India route.

Frenchnaval forces seized the shipafter it was tracked off the Danish coast, during a wave of drone incidents which temporarily closed several Danish airports in September 2025.

There is no claim that the tanker directly launched the drones. But the incident demonstrated that European governments are increasingly willing to act on the risks created by the shadow fleets presence, even if individual incidents remain difficult to prove.

In February 2026, Swedish forces reportedly observed andjammed a reconnaissance dronelaunched near Malm against the French aircraft carrier Charles de Gaulle.

That drone was traced not to a shadow fleet tanker, but to the Russian intelligence vessel Zhigulevsk, but the episodeunderlined that the boundary between commercial shipping, intelligence activity and military pressure is becoming harder to draw.

Russia's hybrid maritime campaign in European waters

Shadow fleet targeted as EU advances frozen assets plan for Ukraine

The cost to Moscow

In terms of a wider European response, NATO has launched theBaltic Sentry operation, while the UK has introduced itsNordic Wardensurveillance measures. Since late 2024, eight European enforcement actions against shadow fleet vessels have been recorded, mainly through boardings and seizures where legal grounds can be established.

Moscow, however, has adapted quickly. Some tankers have been escorted by Russian warships, while dozens of vessels have been reflagged under the Russian registry to make boarding more difficult in legal terms. There has also been increasing use of military-linked personnel aboard commercial tankers.

European action thus raises the cost to Russia of using a shadow fleet, butthe fleet remains central to keeping itsoil revenues flowingdespite sanctions.

Originally published on RFI