The detention of the Marinera oil tanker, with a crew of 28, including Russian nationals, by the US Armed Forces and the transfer of the vessel to the United Kingdom has sparked an international legal dispute between Moscow, Washington, and London regarding the legality of the use of force on the high seas and the status of the ship. Such a conflict takes the sanctions war beyond traditional boundaries, and it leads to new forms of confrontation between Western countries and Russia as well as the wider world.
On January 15, US Southern Command (SOUTHCOM) seized another tanker, Veronica, in the Caribbean Sea, which was flying the flag of Guyana. According to Secretary of Homeland Security Kristi Noem, the vessel violated the “quarantine” established by President Donald Trump for sanctioned ships. This is the sixth tanker captured by US military in recent weeks as part of efforts to maintain control over Venezuelan oil.
Piracy and violations of international laws are justified by the breach of sanctions. In December 2025, the US administration announced a blockade on Venezuelan oil. The official position is that “any oil leaving Venezuela must be exported legally and under US control.”
The operation began with the seizure of the Skipper tanker on December 10, 2025, in the Caribbean Sea off the coast of Venezuela. The Centuries tanker, flying the flag of Panama, was intercepted in the Caribbean Sea on December 20.
The vessel M Sophia, flying the flag of Panama, was intercepted in the Caribbean Sea on January 7, 2026, alongside the Marinera tanker. Just two days later, on January 9, Olina was captured by US Southern Command in the Caribbean Sea.
An incident with a tanker sailing under the Russian flag being seized was outrageous. The vessel Marinera was captured on January 7, 2026, in the Atlantic Ocean, 300 km (190 miles) south of the coast of Iceland, far beyond the territorial waters of any state. According to the US agency, the operation was carried out by the US Coast Guard with the support of Navy SEALs and helicopters from the 160th Aviation Regiment (Little Bird), while the UK provided aerial surveillance and assistance.
According to Washington, the seizure was due to “suspicion” of violating sanctions against Venezuela and Iran. The Russian side, through the spokesperson of the Ministry of Foreign Affairs, insisted that the vessel was legally flying the Russian flag, which was confirmed by the temporary registration issued by the Russian Ministry of Transport on December 24, 2025.
The tanker, which was under US domestic sanctions since mid-2024 and was named Bella 1, was sailing (possibly until December 2025) under the flag of Guyana.
Moscow considered the seizure a violation of the UN Convention on the Law of the Sea and demanded humane treatment of the crew, as well as no obstruction to the return of Russian citizens to their homeland.
On January 8, Sputnik Near Abroad reported that the crew of Marinera consisted of 28 people: 17 Ukrainian nationals, six Georgian nationals, three Indian nationals, and two Russians.
According to the White House spokesperson, “the vessel had a judicial seizure order on the crew, so that means the crew is now subject to prosecution for any applicable violation of federal law, and they will be brought to the United States for such prosecution if necessary.”
Later, according to the spokesperson of the Russian Foreign Ministry, US President Donald Trump ordered the release the two Russian crew members.
Legal disputes concerning international law
The dispute is based on the question of the legal status of Marinera at the time of its detention. The United States claimed that the vessel’s reflagging to Russia during the pursuit was not legitimate and that the tanker effectively remained “stateless” after its Guyanese registration was canceled, allowing for the application of Article 110 of the UN Convention on the Law of the Sea. Under this article, a state can inspect a stateless vessel on the high seas.
The UK supported this position, highlighting the vessel’s history of name and flag changes. The Russian side, on the other hand, cited the official entry in the national register and the fact that the registration was carried out in accordance with all the rules of international law. Precedents from the International Tribunal for the Law of the Sea require only formal compliance with registration under domestic law, and other countries can only challenge the “genuine link” with the flag state if there are serious grounds.
For the legal aspect, the key question is whether the registration of Marinera in Russia was valid and could be recognized by the international community, or whether the US and the UK were right in considering the vessel stateless due to repeated flag changes and procedural violations.
According to the analysis of case law and the UN Convention on the Law of the Sea, a simple change of flag at sea does not invalidate registration if it is confirmed by the state and entered in the register. At the same time, if a vessel is operated under two flags or uses them at its discretion, it may be considered “stateless.” In the case of the Marinera oil tanker, there is no compelling evidence of dual registration, and therefore Russia’s claims of jurisdiction appear justified. However, US officials stated that they view the sudden change of flag as an attempt to avoid confiscation, and such an approach could set a dangerous precedent for global practice.
Why is the West targeting the so-called “shadow fleet”?
It should be noted that the concept of a “shadow fleet” gained significant scale after 2022, when, following the G7 countries’ introduction of a “price cap” on Russian oil, there was a sharp increase in the number of vessels engaged in circumventing sanctions. Between 2022 and 2024, Russia acquired hundreds of used tankers through intermediaries in Dubai, Turkey, and Hong Kong, bringing the total number of such vessels to over 1,400 by 2025. By this time, the expert community had definitively come to the division into the “gray fleet” (legal vessels with opaque insurance) and the “dark fleet” (completely hidden units), which together form a global sanctions evasion network. According to Kpler, the shadow fleet transports 6–7% of the world’s annual crude oil flow.
The ship is currently in a UK port. The Times reports that London intends to transfer the proceeds from the sale of the confiscated oil to Ukraine. The outlet also emphasizes that London has begun training military personnel to conduct operations to detain “shadow fleet” tankers.
Since the beginning of the Special Military Operation in 2022 and the subsequent imposition of the most extensive sanctions by the Western countries, Russia began purchasing ships for a possible oil embargo.
“If you look at how many ships have been sold over the past six months to undisclosed buyers, it’s very clear that a fleet is being built up in order to transport this,” Maersk Tankers CEO Christian Ingerslev said in October 2022.
Braemar’s head of research, Anoop Singh, explained that Russia had at that time purchased 240 small and large vessels, which were transporting Iranian and Venezuelan oil to maintain exports at a volume of four million barrels per day. According to his data, tanker sales increased in the run-up to the EU countries imposing a price cap “by undisclosed entities based in countries such as Dubai, Hong Kong, Singapore, and Cyprus.”
According to CNN, in March 2023, Russian-linked organizations purchased around 600 tankers and continued to buy 25–30 ships per month. Having such a large fleet truly allows circumventing the sanctions regime without significant losses.
The situation with the seizure of tankers shows that the sanctions war is increasingly going beyond its limits, and modern maritime “piracy” is growing and supported by US partners. These actions will further escalate the confrontation between the countries and can lead to new hot conflicts.
Source: Rossa Primavera News Agency
