The Russian tugboat Sarmat spent nearly a week operating near critical underwater cables off the Danish coast, according to observations shared by open source intelligence (OSINT) project Russian Forces Spotter regarding vessel’s movements. Data from the ship tracking platform Starboard Maritime Intelligence reviewed by The Insider confirms that the Russian vessel operated between the island of Læsø and mainland Denmark from Sept. 15 to 22.
The Sarmat (IMO: 8027133) sails under the Russian flag and is owned by Northern Alliance LLC, a company registered in St. Petersburg. According to the OSINT analysts, the Sarmat was towing a jack-up barge fitted with three legs and an excavator – equipment designed for offshore operations and capable of working directly on the seabed. The project reported that from Sept. 18 to 23, the vessel operated between Læsø and mainland Denmark, an area where numerous power and telecommunications cables run.
Starboard Maritime Intelligence data reviewed by The Insider shows that the Sarmat approached the northernmost coast of the Jutland Peninsula on Sept. 12 and remained virtually stationary until the 15th, when it began sailing along the Danish coast between the mainland and Læsø. The Sarmat only began sailing away from the area where the cables are laid on Sept. 22, and by the 24th it was already rounding Norway’s southern coast. As of Oct. 1, the tug was moving northeast along the Norwegian coast toward Murmansk.
As Russian Forces Spotter notes, the repeated movements and the location in which they took place make the Sarmat's activities particularly suspicious. At the same time, the OSINT project stresses that a high risk of sabotage does not mean that an act sabotage actually occurred. When a local ferry asked the Sarmat to move away from its planned route, the Russian vessel replied: “Not possible, in operation.” When asked what kind of work it was doing, it replied: “Towing.” As the OSINT project notes:
“The alert was lifted. But a Russian tug spending days manoeuvring with seabed-capable equipment around critical Danish subsea infrastructure is not something to dismiss as routine.”
The Danish outlet DR reported that Danish authorities formed a local crisis management group and were prepared to respond if any illegal activity by the Sarmat was detected. Authorities learned about the Russian vessel after “a concerned citizen contacted the Læsø municipality” upon seeing the Russian tug.
On Sept. 10, Reuters reported that the UK, U.S. and Norway had disrupted a Russian operation near Svalbard in the spring of 2026 that appeared to be testing new technology for covertly disabling undersea cables.
