After Russia launched a full-scale war against Ukraine in February 2022, Europe and the G7 countries imposed extensive sanctions on the Kremlin’s energy sector, including a ban on insurance, financial and service provision for Russian tankers transporting oil whose value exceeds the price cap. This restriction is intended to deprive Moscow of the export revenues it needs to finance its military operations. However, the Russian oil industry has responded to the restrictions by creating a so-called ‘shadow fleet’ — a network of old, often uninsured and formally registered tankers that circumvent sanctions, change flags and names, hide owners and continue to export hydrocarbons. Consulting firm Windward estimates that in 2025, nearly 700 vessels changed flags between two and six times.
This fleet has become a key supply channel. It now comprises more than 900 vessels. According to data collected by Kpler, in December 2025 alone, the shadow fleet’s tankers transported nearly 5 million barrels per day, equivalent to 11% of global maritime transport, and estimates by Estonian experts suggest that up to 60% of Russian maritime oil exports now pass through the Baltic Sea.
The term ‘shadow fleet’ reflects not only the legal uncertainty surrounding these vessels, but also the danger they pose, as the disabling of automatic identification, falsification of data and uncertainty of insurance coverage make such tankers a potential source of environmental hazards and threats to maritime safety. European states believe that this creates a risk of accidents, oil spills and even direct damage to critical infrastructure, such as underwater communications and cables. This is evidenced by both official reports and a number of incidents that have received widespread publicity.
In December 2024, Finnish authorities detained the tanker Eagle S, suspected of cutting underwater communication and power cables between Finland and Estonia. This incident was one of the reasons for increased demands for control of the shadow fleet. After the vessel damaged at least four cables, according to the authorities, Finnish law enforcement officers detained it for investigation and to ensure the security of communications.
Another high-profile case occurred in May 2025 with the tanker Jaguar, which the Estonian Navy attempted to inspect off the Baltic coast. The crew refused to cooperate, and as a result, according to officials, a Russian Su-35 fighter jet briefly entered Estonian airspace in response to attempts to detain the vessel. The incident caused diplomatic tension and discussions at the NATO level.
Another example was the activities of the tanker Kiwala, which was detained by the Estonian authorities in April 2025 for violating registration rules and not having a valid flag, which became an argument for tightening control over shadow fleet vessels in European waters.
In addition to the Baltic Sea, tensions surrounding such vessels were also observed in the Mediterranean Sea: in early 2026, the French navy intercepted and sent the tanker Grinch, suspected of being involved in the shadow fleet, to the port of Marseille-Fos.
In addition, there are numerous reports that ships belonging to the shadow fleet are manipulating navigation and satellite positioning systems, which is characterised as an action that affects the safety of shipping in the Baltic and North Seas. The United Kingdom and a number of allied states have sent a warning to the International Maritime Organisation that such manipulations jeopardise hundreds of maritime operations and could lead to serious accidents.
These incidents coincided with a lengthy process of expanding sanctions lists. In the European Union, by the end of 2025, 568 tankers will be subject to sanctions, prohibiting them from entering EU ports and receiving key services.
These processes culminated in an official statement by 14 European countries (Belgium, Denmark, Estonia, Finland, France, Germany, Iceland, Latvia, Lithuania, the Netherlands, Norway, Poland, Sweden and the United Kingdom) on the need for tough measures against ‘shadow fleet’ tankers in the Baltic and North Seas. In a joint document, the countries demanded that ships sail only under the valid flag of one state and have all the necessary documents, including insurance and a safety certificate, otherwise they will be considered stateless and will not be able to move legally. The statement also noted that interference with satellite navigation and positioning systems is an illegal act.
This decision was a logical continuation of the long evolution of sanctions policy, including the preparation of EU legal instruments for the detention of such vessels, as well as the expansion of powers to inspect and arrest suspicious vessels in accordance with international maritime law. European states are also coordinating efforts to exchange information in order to effectively detect and block illegal shipments.
A practical example of these tougher measures was the ban on the Russian tanker Tavian entering the Baltic Sea, which was first applied in January 2026 and became a symbol of the new practice of European pressure on the shadow fleet.
For Russia, the shadow fleet has long served as a tool for circumventing sanctions and maintaining oil exports to foreign markets. However, increased control by European countries in the Baltic and North Seas is already affecting the revenues of Russian oil companies and budget revenues from energy exports. Thanks to the introduction of sanctions, including a price cap on Russian oil and sanctions against shadow fleet vessels, Russia’s revenues from energy sales have fallen significantly. According to European Union data, Russia’s revenues in 2025 were 13.7% lower than in 2023 and 20.3% lower than in 2022.
Analytical reviews show that until mid-2025, export revenues from hydrocarbons fell to their lowest levels since the start of the full-scale war in Ukraine, which is a consequence of both falling world prices and restricted access to Western markets and supply insurance.
Taken together, these factors—lower prices for exported oil, restrictions on the insurance and logistics services market, and a ban on shadow fleet tankers entering EU ports—are putting pressure on foreign exchange earnings, the budget deficit and the deterioration of the investment climate in the oil and gas sector, which has traditionally been the main source of income for the Russian economy.
In addition, the measures affect not only the tankers themselves, but also related companies, insurance structures and financial intermediaries, which increases logistics costs and complicates the work of market players. This, in turn, affects transport costs and reduces the attractiveness of maritime exports for Russian customers and partners. Legal risks and insurance premiums for such operations are constantly increasing, pushing owners to seek less secure routes.
Europe’s decision to close the Baltic Sea to the shadow fleet stems from years of evolving sanctions policy, a series of dangerous precedents, and growing concerns about the safety and legality of shipping. The economic and political consequences of these measures are already apparent and will intensify as they are implemented, affecting global energy flows and international relations.