Russia Detains Oil Tanker Leaving Estonian Port in Tit-for-Tat Seizure

Russia detained the Liberian-flagged oil tanker Green Admire on May 18 in the Gulf of Finland after it departed from the Estonian port of Sillamäe and entered Russian territorial waters.

This is according to Estonia’s Transport Department, as reported by national broadcaster ERR.

The tanker was en route to Rotterdam, carrying a shipment of shale oil. Its chosen route, although passing through Russian waters, had been previously agreed upon by Russia, Estonia, and Finland for navigational safety due to shallower waters on the Estonian side of the gulf.

Estonia’s Foreign Minister Margus Tsahkna stated, “This navigation path was established by mutual agreement between Russia, Estonia, and Finland. It does not strictly follow national borders but is safer for large ships.”

Russian authorities stopped the vessel shortly after midnight, and by 4 a.m., Green Admire was anchored near Gogland Island in the eastern Gulf of Finland. As of May 19, it remains stationary there. Russia has not yet issued any public statement on the seizure.

The Estonian Transport Department emphasized that this is the first time a vessel has been detained in Russian waters while following the agreed shipping corridor. The route had been considered the safest and shortest option for tankers traveling to or from Sillamäe.

The tanker is owned by Greece-based Aegean Shipping. Estonia plans to reroute future tanker traffic through its own territorial waters with pilot support, even though this alternative is more difficult for larger vessels due to shallow waters.

Tsahkna linked the incident to growing pressure on Russia’s so-called shadow fleet—a network of vessels used to bypass international oil and gas sanctions. "This is clearly connected to the pressure we and others in the Baltic region are applying," he said. "Russia is finding it increasingly difficult to conduct this business."

Estonia has recently detained multiple tankers linked to Russia’s shadow fleet. In April, it held the Kiwala, sailing under the flag of Djibouti, and on May 14, its navy attempted to stop the Jaguar, suspected of sanctions violations. The Jaguar ignored Estonian attempts to board it, prompting Russia to dispatch a Su-35 fighter to escort the ship.

Following the Jaguar incident, Baltic Sea countries agreed to increase preemptive interception of shadow fleet tankers, particularly in Danish waters with support from Germany and Sweden.

Despite the latest seizure, Estonia has opted for a measured response. “We don’t see a need to summon the Russian chargé d’affaires,” said Tsahkna. “The tanker complied with orders. There was no force used. Still, we are watching carefully to see if it will be allowed to continue.”

He added, “Russia remains unpredictable and genuinely dangerous. We must respond calmly but stay alert.”