A ship can disappear from radar in a few minutes, but some stories remain afloat for years. Even when the wreck ends up at 2,500 meters deep, in a point in the Mediterranean where recovering a black box becomes an expensive, risky operation, almost like a military mission. The Ursa Major, a Russian cargo ship that sank on 23 December 2024 between Spain and Algeria, initially seemed like a fairly opaque affair: an explosion in the engine room, two crew members missing, fourteen survivors taken to Cartagena, a Russian warship arriving on site to take charge of the situation.
Then the picture got heavier. Because inside that ship, officially loaded with port cranes and icebreaker components, there may also have been pieces of nuclear reactors similar to those used in submarines. And the real destination, according to the most delicate reconstructions, could have been North Korea.
Prudence is essential here. The wreck was not inspected, the cargo was not recovered, the governments involved said little or nothing. However, some elements are concrete enough to make the story difficult to dismiss as simple intelligence fog. In a written response to opposition MPs, the Spanish government indicated that the ship’s captain, when questioned after the rescue, declared the presence of components for two nuclear reactors on board, adding that there was no nuclear fuel. The Spanish authorities, busy rescuing the crew and searching for the two missing, were unable to physically verify the cargo. The sea, in certain cases, becomes an armored archive.
The official cargo
On paper, the Ursa Major left St. Petersburg on December 11, 2024, bound for Vladivostok, in the Russian Far East. An enormous crossing, from the Baltic to the Pacific, passing through the Mediterranean and Suez. The declared cargo included two large port cranes, heavy components intended for icebreakers, 129 empty containers and technical material. The ship was controlled by Oboronlogistika, a company linked to the Russian Ministry of Defense, which had already come under US sanctions for its relations with Moscow’s military apparatus.
This alone would be enough to remove the air of a normal commercial incident from the affair. The Ursa Major was no ordinary freighter carrying refrigerators and garden furniture. It was a heavy-lift ship, built for heavy loads, used in the past also along sensitive routes for Russian logistics. On December 22, when it was off the coast of Spain, it suddenly slowed down. The Spanish rescuers contacted her to understand if there were any problems. A reassuring response came from the ship: everything was under control. About twenty-four hours later, the situation suddenly changed. The ship veered sharply and issued an urgent call for help.
According to the owner company, the cargo was hit by three consecutive explosions on the starboard side, in the stern area. The company itself immediately spoke of a “targeted terrorist attack”, describing a hole measuring approximately 50 by 50 centimetres, just above the waterline, with the edges of the metal facing inwards and fragments on the deck. It is a Russian version, so it should be taken for what it is: a biased position, formulated by a person directly involved. However, it coincides with an important material fact: the ship suffered sudden damage and began to tilt.
The explosions after the rescue
The next scene seems to come out of a spy novel written by someone with little desire to appear credible, and instead it lies within the acts and reconstructions available. Spain sent rescue vehicles. A Russian warship, the Ivan Gren, also arrived and imposed a safe distance around the Ursa Major. The survivors were recovered and taken to Cartagena, including the captain, who would later provide Spanish investigators with crucial details about the cargo.
Then, according to the most recent reconstruction, the Russian ship would have fired illuminating rockets or flares near the damaged cargo. Immediately afterwards, Spanish seismic sensors recorded a series of explosions, followed by the final sinking of the Ursa Major. Here we enter the most slippery part of the story. Some hypotheses speak of a supercavitating torpedo, that is, a weapon capable of moving at very high speeds creating a gas bubble in front of it. One naval analyst also pointed to a simpler possibility: an explosive charge applied to the hull. Words matter: hypotheses, not sentences.
The point, however, remains weighty. If a Russian ship was indeed transporting nuclear components for submarines to North Korea, the case would move beyond the scope of a maritime accident and into that of military proliferation. Pyongyang has been working for years on building more advanced naval capabilities, while Moscow, after the invasion of Ukraine, has increasingly tightened its relationship with North Korea. In this context, even simple industrial “coverage”, such as cranes and icebreaker parts, becomes material to be read with suspicion. Geopolitics sometimes travels like this: not with great speeches, but with containers, hatches, declared routes and ports that perhaps were not the real ones.
There is also the detail of the alternative destination. The captain reportedly told investigators that he expected a diversion to Rason, a North Korean port near the borders with Russia and China, instead of continuing towards Vladivostok. This step remains one of the most delicate, because it links the suspicious cargo to a possible delivery to Pyongyang. At the moment there is no public evidence of radioactive contamination and this is an important fact: talking about nuclear components does not automatically mean talking about fissile material or fuel on board. The difference, in a story like this, avoids turning a serious suspicion into an apocalyptic headline.
The seabed is convenient for many
A week after the sinking, a Russian research vessel, the Yantar, reportedly remained in the area of the wreck for about five days. According to a source cited in the investigative reconstruction, four other explosions were recorded in that period, perhaps linked to an attempt to destroy what remained on the seabed. Here too we are in the field of attributions, but the overall design has its own dark coherence: a ship sinks, the cargo is too sensitive to be left legible, the wreck becomes a problem to be buried twice.
In the following months, US aircraft specialized in detecting nuclear traces flew over the area along routes consistent with an interest in the site, although a similar flight had been recorded months earlier and the US base concerned did not provide details. This makes the picture even less clean, less graspable. Too many pieces fit together, none is enough alone. It’s the kind of story where every confirmation opens a hole next to it, and every silence weighs almost as much as a statement.
For an Italian reader, accustomed to seeing the Mediterranean described above all as a sea of migratory routes, tourism, gas pipelines and submarine cables, this story shifts the frame. That stretch of water between Spain and Algeria becomes a zone of friction between powers, a place where commercial traffic can intersect military operations, satellite surveillance, intelligence, rescue ships and naval equipment. The sea, from afar, always seems open. Up close it is full of invisible boundaries.
The Ursa Major is now still on the seabed. Above remain the official versions, the half-admissions, the failed denials, the suspicious routes, the survivors who returned to Russia, the two deaths, a load that no one can easily control anymore. The history of nuclear reactors for North Korea remains within this gray area: documented enough to make noise, incomplete enough that it cannot be closed with a definitive formula. At 2,500 meters deep, certain questions do not disappear. They just become more convenient to leave there.
You might also be interested in:
