The Russian navy is facing enormous pressure, largely due to President Putin’s overly ambitious attempts to claim great power status.
The most obvious trouble spot is the Black Sea, where the Russian fleet has retreated from danger and been forced to enter distant ports, largely due to the effectiveness of Ukrainian drone attacks. Even more striking, given that Ukraine lost most of its aging warships in the early stages of the conflict, the end result is that Russia has lost control of the Black Sea, and Ukraine has now been able to resume imports and exports through Odessa and other ports in the southwest of the country. The remaining capabilities that the depleted Black Sea Fleet retains are the ability to launch cruise missiles from the eastern Black Sea and to deter offensive naval operations that Ukraine might otherwise attempt to launch along the Crimean coast.
The situation in the Mediterranean is similar. The Russian Navy has lost the home port for its former Mediterranean flotilla at Tartus, where it may have retained a beachhead, but apparently not the right to berth and service warships. This loss is compounded by the Russian Navy’s inability to maintain its flotilla in the Mediterranean by rotating warships through the Bosphorus, which Turkey has unilaterally closed to all warships, as is its right in wartime under the 1936 Montreux Convention. As a result, Russia’s naval presence has been reduced from a permanent force of about five warships and a submarine operating from Tartus to the occasional deployment in the Mediterranean of one or two frigates and a submarine drawn from the Baltic and Northern Fleets, as well as a residual presence of a few tankers and intelligence-gathering vessels operating independently.
While the situation in the Black and Mediterranean Seas has been evident for some time, the Russian Navy’s predicament has worsened significantly in recent months. A new pressure has been a concerted and coordinated international campaign to restrict Russian oil exports using dark fleet tankers.
In March 2023, Lloyd's List defined dark fleet tankers as vessels "15 years or older, anonymously owned and/or with a corporate structure designed to conceal beneficial ownership, used exclusively in the sanctioned oil trade, and engaging in one or more of the fraudulent shipping practices outlined in the U.S. Department of State's guidance issued in May 2020." The transportation of Russian oil by accurately registered tankers operated by known owners and agencies does not necessarily qualify a tanker as a "dark fleet," as such vessels may legitimately transport Russian oil purchased at prices below $60 per barrel, above which Russian oil is subject to sanctions. However, more than 700 tankers have been officially sanctioned by the US, UK and EU authorities, and Lloyd's List estimates that the dark fleet accounts for around 10% of the world's tanker tonnage.
In recent months, measures have been stepped up to restrict the operations of illegal tankers.
Denmark, without citing membership in the dark fleet, has begun to challenge the insurance status of dark fleet tankers at the Skagen anchorage and in the Øresund Strait. Under the 1857 Copenhagen Treaty, ships have the right of innocent passage through the Danish Straits. But the Danish Maritime Authority now says it will board ships if it has information "that the safety or working conditions of seafarers do not comply with international regulations, including mandatory insurance requirements." It justifies such actions by the need to protect seafarers and the environment, especially in confined waterways where the consequences of an accident or oil spill can be dire. The UK takes a similar approach in the English Channel, imposing sanctions on ships that fail to respond properly to an average of 40 radio requests for confirmation of insurance status received each month. In April, Estonia detained the Djibouti-registered tanker Kiwala (IMO 9332810, now Pushpa, registered in Malawi), off Tallinn, until safety deficiencies were rectified, before allowing the tanker to continue on to the Russian port of Ust-Luga.
The actions are a test of the innocent passage provisions of the UN Convention on the Law of the Sea, and whether they will succeed or not has yet to be legally – and practically – proven. But Russia is heavily dependent on the sale of its oil to finance its military economy. This fiscal need is becoming increasingly urgent as signs of economic weakness emerge; for the first time since 2022, Russia’s quarterly GDP fell (by 0.6%) in the first quarter of 2025. As a result, Russia has had to take measures to protect its economic interests and the revenues of its dark fleet at sea.
In April, the Baltic Fleet conducted exercises involving 11 warships, a submarine and a destroyer, practicing the task of preventing boardings on civilian vessels under escort. The Finnish Ministry of Defense reported in May that Russian naval vessels had begun escorting dark fleet tankers transiting the Gulf of Finland. The Russian Steregushchy-class corvette Boykiy (F532) escorted the tankers Sierra (IMO 9522324) and Naxos (IMO 9336426) through the English Channel in late June. These and other similar escort duties in themselves further strain the availability of Russian naval vessels and create additional overhead costs for transporting oil. But another complication is that dark fleet tankers are present all over the world, and the Russian fleet cannot be everywhere at once. There are bottlenecks around the world through which the dark fleet must transit, and where the Russian fleet will find it difficult to maintain an escort presence.
While the legality of the interceptions is under investigation, the “dark fleet” also faces a more immediate threat. In late June, the tanker Vilamura (IMO 9529293, registered in the Marshall Islands) was damaged by an explosion near Benghazi. Over the past year, the Vilamura has been seen loading at two Russian oil terminals: Ust-Luz on the Baltic Sea and Novorossiysk on the Black Sea. This is the fifth foreign-flagged oil tanker to be hit by explosions after visiting such Russian ports. These attacks, because they would weaken Russia economically and reflect Russian attacks on Ukraine’s economic interests, may be seen by many as legitimate in the context of the war between Russia and Ukraine.
There has been no serious incident so far related to attempts to stop the activities of the dark fleet, which trades in Russian and Iranian oil. Given all probabilities, such an incident is likely to occur in the near future, and the pressure is felt most strongly by the strained and struggling Russian fleet.