14 shadow tankers, 418 hours, no stops

Somewhere off the Bulgarian and Romanian coasts, tankers flagged as part of Russia's shadow fleet keep passing through. They sail in, they sail out. Between January and August 2026, at least 14 such vessels spent a combined 418 hours in the waters of two EU member states, according to a Greenpeace Bulgaria investigation using Lloyd's List Intelligence tracking data (Greenpeace Bulgaria, Fakti). None were stopped. None were boarded. None were detained.

That sounds like an enforcement failure. It isn't, automatically. The EU can name ships on sanctions lists. Coastal states still need a legal reason to stop them.

Why presence alone can't justify detention

The 14 vessels appear on Lloyd's List's shadow-fleet database, which flags tankers for deceptive practices tied to sanctioned oil cargoes (Greenpeace Bulgaria). But the published data does not include vessel-by-vessel tracking, cargo histories, insurance status, or evidence that any of the 14 made port calls, transferred cargo, or caused pollution in Bulgarian or Romanian waters.

International maritime law protects a principle called innocent passage: ships may transit another country's territorial seas without interference, under the UN Convention on the Law of the Sea (UNCLOS). A sanctions listing alone does not override that right. A tanker crossing the Black Sea without stopping or transferring cargo has the same passage right as any other vessel. As SWP Berlin concluded, listing creates political pressure but not a universal power to seize (SWP Berlin).

The emotional anchor of Greenpeace's campaign is the Kairos, an abandoned sanctioned tanker near Burgas. Activists painted its hull after satellite imagery showed slick-like traces nearby (Greenpeace Bulgaria Kairos, Cherno More). Bulgarian maritime authorities said subsequent checks found no active pollution. The dispute remains open.

Where enforcement works and where it doesn't

Romania's response exposes the gap. The Romanian Naval Authority said no sanctioned vessel had entered Romanian ports after its listing date (DottoTV, Radio Constanta). That answers one question: port access. It does not address what moves through Romania's exclusive economic zone, the wider waters where a state has resource and pollution rights but not full territorial control.

ProTV reported that Romania's Coast Guard received over 1,200 ship-to-ship transfer notifications since May 2022. The Coast Guard said no inspections were needed because the ships had notified under pollution-prevention rules (Stirile ProTV). Notification, in other words, was treated as compliance.

Denmark shows what enforcement looks like when states use the powers they actually have at ports and anchorages. Sitting on the Baltic chokepoint, Copenhagen recorded 292 journeys by shadow-fleet tankers through Danish waters in 2025 (gCaptain). Danish authorities inspected 79 tankers at the Skagen Red anchorage and detained four (Sofart). Denmark also introduced insurance-certificate checks for loaded tankers leaving the Great Belt, feeding missing documentation into sanctions work (Folketinget). Enforcement bites at anchorages and chokepoints. In open water, ships simply pass through.

The service levers that could make sanctions bite

The deeper bottleneck sits not on the Black Sea coast but in Athens and Valletta. Greek-linked operators earned at least $3.8 billion over three years from Russian crude trade, according to Financial Times analysis (Fortune Greece). When the EU's 21st sanctions package tried to restrict maritime services (insurance, brokering, shipping management, finance), Greece blocked the deal until it secured carve-outs for Russian LNG transport (Naftemporiki, News247). EU sanctions require unanimity in the Council (where foreign ministers of all 27 member states must agree), so one country can hold up the entire package. Greece used that power.

The EU has steadily added ships to its sanctions lists. The 21st package gave member states new authority to confiscate cargo from detained shadow-fleet vessels (Skuld, Gard). But cutting European maritime services carries a tradeoff: it could push cargoes onto older ships, opaque flags and non-Western insurers, making the fleet harder to see and harder to insure safely (Brookings).

The 14 tankers and their 418 hours trace a problem the EU has built sanctions rules to address but left coastal states to absorb. Bulgaria and Romania bear the environmental risk of ageing, under-insured vessels passing through their waters. Greece controls the service levers that could squeeze the fleet's economics. Surveillance alone is being mistaken for enforcement. Until Sofia and Bucharest adopt the tools Denmark has proven work (anchorage inspections, insurance checks, documented pollution triggers), they will keep counting hours while the tankers keep passing.