450 transits by suspected Russian 'shadow fleet' vessels have been recorded in Irish waters in the first seven months of this year.
According to satellite data from maritime intelligence firm Windward, nearly 250 ships believed to be part of the covert fleet passed through Ireland’s Exclusive Economic Zone (EEZ) between January and July.
The vessels are linked to efforts by Russia to sidestep EU and US sanctions imposed in response to its invasion of Ukraine.
These sanctions target the export of Russian oil, which continues to fund the country’s war effort.
Many of the tankers are described by Windward analysts as ageing, under-maintained, and lacking proper insurance.
They often operate under “flags of convenience” from countries like Liberia, Panama, Malta, and the Marshall Islands, jurisdictions known for minimal oversight.
Windward’s analysis found that more than 70 of the ships that transited through Irish waters were directly listed in EU and US sanctions databases.
During the first five months of the year alone, 40 vessels had clear Russian ties, including several flying the Russian flag and others owned by Russian companies.
Their passage through Irish waters, often without docking, has raised the alarm among maritime experts and political observers.
Ireland’s EEZ, which stretches around 370 km off the west coast, is a critical maritime zone with several major international shipping lanes and undersea cables.
Experts warn that the continued movement of these ships through Irish waters undermines international efforts to isolate Russia economically.
“These ships are like vehicles on Irish roads without an NCT or insurance,” said Tony Cudmore, a retired brigadier general with the Irish Defence Forces, to RTE.
“They’re poorly maintained, possibly crewed by underqualified personnel, and pose a real danger—not just to the environment, but to Irish sovereignty.”
Some shadow fleet vessels have been linked to damage to subsea infrastructure, particularly in the Baltic Sea.
Recent examples include Sweden seizing a ship suspected of damaging a cable linking the country with Latvia, at the beginning of the year.
Furthermore NATO launched its new 'Baltic Sea Mission' this year, after numerous cables were damaged in 2024.
Another example is an open investigation by Finland, into suspected Russian sabotage into cables damaged between their country and Estonia.
There are worries that similar incidents could happen off the Irish coast, where undersea cables are vital to global communications and trade.
Several of the ships tracked this year have engaged in suspicious or high-risk behaviour, including turning off their location transponders or conducting ship-to-ship oil transfers.
One such vessel, the Valentin Pikul, passed through Irish waters in March and was later involved in oil transfers near Murmansk.
Others, including the Russian-flagged Bratsk, Belgorod, and Primorye, were recorded going “dark” for periods while navigating near Donegal, Clare, and off the western seaboard according to Windward.
The Irish Defence Forces said they monitor maritime activity continuously and share intelligence with national and international partners.
The Irish Coast Guard, through its search and rescue and pollution response roles, also tracks ship movements and has detected multiple sanctioned Russian vessels in Irish waters since the start of the year, according to RTE
A recent EU directive requires all vessels transiting through EU EEZs, including Ireland’s, to provide valid proof of insurance, even if they don’t dock.
However, enforcement of such rules remains challenging.
Earlier this year, German authorities seized a Panama-flagged tanker off the Baltic coast carrying 100,000 tonnes of Russian oil.
The incident has been cited as an example of the type of enforcement Ireland could pursue.
Despite sanctions from the EU, Britain and the US, including bans on over 400 Russian-linked tankers, Russia’s oil export levels have remained relatively stable.
The International Energy Agency reported an average of 7.5 million barrels per day exported in 2024, only slightly down from pre-war figures.
Professor John O’Brennan of Maynooth University said the persistence of shadow fleet operations highlights a gap in enforcement across EU member states.
“Russia has successfully exploited inconsistent national responses,” he said. “If countries like Ireland don’t step up their enforcement efforts, these vessels will continue to slip through the cracks.”
