Russia Expands Arctic Oil Shadow Fleet With Dark STS Transfers in Sea of Japan

Russia has conducted two dark ship-to-ship (STS) transfers involving oil cargoes that traveled through the Northern Sea Route, highlighting the increasingly complex logistics to move Russian crude to Asian markets via the Arctic.

Satellite analytics company SynMax identified two STS operations involving four oil tankers, according to data and imagery provided to gCaptain. The vessels were detected conducting transfers well offshore between Russia’s Far East and the Korean Peninsula.

The tankers Jagger and Mirabel both traveled through the Russian Arctic after loading crude earlier this summer. Jagger loaded near Murmansk on July 20, while Mirabel departed Primorsk in the Baltic Sea on July 24, according to AIS data. Both subsequently transited the Northern Sea Route.

On September 7 Jagger transferred its cargo to the tanker Navistar, while Mirabel delivered oil to Lumin. Neither receiving vessel was transmitting AIS data during the transfers, according to SynMax.

The operations took place well south of Nakhodka Bay, where Russian tankers have previously conducted STS transfers after completing Northern Sea Route voyages.

“These are the first two STS events we have detected in this particular area, farther south than Nakhodka Bay,” a SynMax representative said. “[The transfers] stand out as they occurred considerably farther offshore than the activity we previously observed around Nakhodka Bay,” the company continued.

The use of dark STS transfers has become an important part of Russia’s oil export system since Western sanctions were imposed after Moscow’s invasion of Ukraine. Ship-to-ship transfers can obscure a cargo’s origin and allow oil to be moved between vessels, sometimes with AIS transponders switched off.

Industry analysts estimate that shadow tankers now carry a substantial share of Russian seaborne oil, with sanctioned shadow vessels accounting for 62% of Russian crude exports in July

SynMax also identified tankers Ligovsky Prospect and Primavera delivering oil directly to Chinese ports via the Arctic. Ligovsky Prospect reached Dongying, while Primavera sailed to Lanshan. Both were detected without AIS signals while in port and appeared to subsequently begin return voyages toward the Arctic.

The activity comes during a particularly busy summer for Russian Arctic oil exports, including routing vessels just 500 nautical miles from the North Pole. Seven tankers had already carried about 6 million barrels through the NSR by early August, nearly half the volume transported via the route during all of 2025.

The Arctic oil trade is likely to grow further. Russia’s Rosneft commissioned the giant Vostok Oil project on September 6, loading the first crude from the new Bukhta Sever terminal onto an Arc7 ice-class tanker. The project is designed to ship 30 million metric tons of oil in the second half of 2027, rising to 50 million tons by 2030, with infrastructure ultimately capable of handling up to 100 million tons annually.

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