The Shadow Fleet Gets that Sinking Feeling

A Growing Safety Hazard

A hidden fleet of aging tankers is quietly reshaping the geopolitics of energy transport, while posing an unprecedented environmental hazard as a result. This is due to Russia's use of a Shadow Fleet to evade sanctions and support its ongoing invasion of Ukraine.

The Rise of Russia's shadow fleet has resulted in a sprawling network of ostensibly privately owned, barely regulated vessels, transiting the world's oceans. Whilst these ships enable the movement of embargoed supplies, slipping under the radar of international scrutiny, many are old civilian ships pressed into service far beyond their original design limits. Outdated safety systems, uncertain insurance and the use of the most dubious flags of convenience raise the specter of accidents that could devastate the marine environment and threaten regional stability. Now there are signs that at least some authorities are taking action to prevent this.

Recent Accidents and Spills

The dangers posed by the aging fleet have already resulted in notable accidents. In December 2024, two tankers of the Shadow Fleet were sailing the Black Sea, hauling mazut, a dirty low-quality heavy fuel oil made from the left-overs of crude oil refining, commonly used in Russia. The tankers, Volgoneft-212 and Volgoneft-239, were over 50 years old, and originally intended only for inland shipping, with a design never intended for the rough open water operations that the Shadow Fleet needed them for. The Volgoneft-239 in particular had its documentation suspended, and it should never have been in service at all. On the 15th December, the vessels sailed into a storm off the Kerch Strait, and their obvious shortcomings were laid bare. Hit by large waves, the Volgoneft-212 simply snapped in half and sank with its 4,300 tons of mazut leaking into the sea, while the Volgoneft-249 began to break up and drifted out of control until it was driven aground. The results were horrific, one crewman was killed, thousands of tons of mazut were spilled, with the damage to the environment estimated to be around $1bn.

Other accidents have occurred, fortunately without the loss of life. In January 2025, the Shadow Fleet tanker Eventin was carrying 99,000 tons of oil through the Baltic Sea when the vessel lost power and steering simultaneously. The ship drifted out of control until the German authorities sent tugs to rescue it. German foreign minister, Annalena Baerbock, called the incident "a danger to security and tourism in the Baltic Sea" and said that Russia was endangering European security "not only with its war of aggression on Ukraine" but "even with dilapidated oil tankers".

In December 2024, the Shadow Fleet vessel Eagle S dropped an anchor and dragged it along the sea bed, severing a power connection between Finland and Estonia, along with several data cables. It is unclear whether this was due to mechanical malfunction and incompetence or actual sabotage, but the cost ran into tens of millions of dollars. The Captain and first and second officers of the Eagle S have been charged by Finnish authorities, who are also pursuing damages against the purported owners; however, the use of front companies and lax flag of convenience registration are hampering this (while the ship is Russian controlled, the 'owner' is an opaque company registered in the UAE).

Obscuring Identity

To conceal the perilous condition of many of the vessels in the Shadow Fleet, dubious or downright illegal methods to obscure their true identity and condition are being undertaken. Some of these are crude, such as simply painting over the ID on the Hull with something false, but more sophisticated means are also being used. Lloyd's List has identified since June at least seven tankers that have changed their Maritime Mobile Service Identity (MMSI) numbers to ones that are not actually allocated to any country. The MMSI should show which country the vessel is registered in, but the Shadow Fleet are flouting this. For example, the tanker Symphony started to transmit stateless MMSI in June, and used two different, entirely fake IMO numbers along with, and in any other messages. Another vessel, the Swiftsea Rider (already sanctioned by the EU and UK), started behaving in a similar way in July. Lloyd's also noted the existence of fake ship registers, that are doing "booming business" supporting Shadow Fleet operations supporting Shadow Fleet operations and "enabling extreme flag hopping practices".

More recently the Shadow Fleet vessel Boracay made the news when it was seized by French authorities as part of investigations into drone activity targeting Denmark. What is often not reported, is that this vessel had already been stopped and investigated by Estonia in April, while shipping oil from Russia to India. The Estonian enquiry was prompted because the ship had changed its name to Pushpa, falsely claimed a Djibouti flag, suffered multiple technical deficiencies, and its crew could not prove its true nationality

Regulators Respond

These shady and potentially dangerous practices are causing concern worldwide, even countries actively involved in trade with the Shadow Fleet are getting worried. One of China's largest oil ports, Huangdao in Shandong province, is a common destination for Shadow Fleet oil tankers. In a clear response to the dubious operations of he fleet, the port will be introducing new rules from November 2025. These rules are designed to protect the area from unsafe vessels; any vessel that has invalid or expired certificates, or that has experienced pollution incidents or accidents in the past year, will be banned. A scoring system will be introduced rating every ship on categories such as age, pollution insurance and classification, and those not meeting the grade will be banned - ships that are thirty years old or more will automatically be banned. Perhaps most pointed of all, any that have used false IMO numbers will automatically be banned - a measure clearly taking aim at Shadow Fleet operations.

Other countries have started to expand Port-State Control (PSC) to check on vessels simply passing through their waters. In particular, checks on insurance certification for vessels transiting chokepoints such as the Danish Straits, English Channel, Gulf of Finland etc are clearly increasing in in response to the rise in worrisome vessels. Additionally, the United Kingdom, Denmark, Sweden, Finland, Poland and Estonia are coordinating to inspect insurance certificates, share data and take joint measures against suspicious ships.

Key Take-Aways

• Rapid, unchecked growth - Russia's Shadow Fleet new comprises hundreds of vessels, many ageing, privately-owned tankers operating under weak flag-state oversight.
• Serious safety and environmental risks - The fleet's old hulls, substandard and outdated safety systems and dubious insurance have already caused major spills (e.g. the 2024 Black Sea mazut disaster).
• Recent high-profile incidents - Eventins's drift in the Baltic, Eagle S's anchor drag incident, and the seizure of the Boracay highlight the breadth of the threat.
• Regulatory push-back - Ports such as Huangdao (China) and a coalition of EU/UK PSC authorities are introducing stricter certification rules, age limits and bans on vessels with falsified documentation.
• Economic and geopolitical stakes - The Fleet undermines the safety of marine ecosystems, threatens regional energy security and complicates sanctions enforcement against Russia.
• What's needed next - Greater flag-state accountability, and sustained international cooperation to prevent other catastrophic accidents.

Looking Ahead

In short, the Shadow Fleet's unchecked growth is turningn a handful of aging, poorly-maintained vessels into a systemic maritime hazard, threatening ecosystems and regional stability alike. Recent spills, near-misses and the increasingly sophisticated attempts to conceal ship identities have finally prompted ports, insurers and national authorities to tighten inspections, ban falsified documentation and introduce stricter certification regimes. While these steps mark an important shift toward accountability, sustained cooperation among coastal states, tighter flag-state oversight and transparent ownership registers will be essential if the fleet's dangerous legacy is to be erased before another catastrophic incident occurs.