Europe's crackdown halves shadow fleet ships sailing under false flags, report says

Detentions have helped cut the number of ships in Moscow's shadow fleet flying a false flag to less than half between last October and June 2026, according to a report by the Center for Research on Energy and Clean Air (CREA) think tank published on Sept. 25.

The Western crackdown against shadow vessels sailing under false flags has forced 107 to flock to the Russian flag registry since January 2025, leaving them with few other options as open ship registries tighten oversight.

The shadow fleet is a group of aging, poorly insured tankers used by Russia to ship out its oil in violation of international sanctions. Western governments have also accused Moscow of using the fleet to support its hybrid war against Europe.

European countries have become increasingly assertive in enforcing their sanctions against the fleet, with France, Sweden, Belgium, and the U.K. boarding suspected shadow fleet vessels that entered their territorial waters.

Shadow fleet ships have traditionally relied on open registries as they are cheap, lightly regulated, and make it easier to conceal the vessels' true ownership.

But countries running the open registries, such as Panama, Comoros, and others, have tightened oversight amid Western pressure.

"Following pressure from sanctioning jurisdictions, Barbados and Palau removed all sanctioned 'shadow' vessels from their registries, while Panama cut the number of sanctioned 'shadow' vessels in their registries by almost two-thirds since May 2025," the report read.

This has forced many shadow fleet vessels to sail under false flags, rendering them legally stateless and giving European countries grounds to detain them.

The most recent interception took place on Aug. 30 when an EU naval mission in the Mediterranean boarded the oil tanker MV Sun, suspected of belonging to the shadow fleet.

Following the crackdown, the number of shadow vessels flying false flags went from its peak of 101 in October 2025 to just 45 by the end of June, the CREA report read.

At the same time, the Russian ship registry surged by 36% since the start of last year to 382 by the end of June 2026.

Eighty-seven percent of the newly Russian-flagged vessels were already sanctioned, and 56% flew at least one false flag before being hit by sanctions and hoisting the Russian flag, according to the report.

Nevertheless, the pivot toward the Russian registry has slowed since the December 2025 peak, with only three new additions in June.

Adopting a Russian flag effectively makes the shadow fleet vessels immune to European interceptions and "renders obsolete the sanctions mechanism European navies have used to interdict them," CREA analysts say.