Denmark is Tracking Stateless Tanker as it Transits Straits
Danish authorities confirmed that they have identified a tanker that they believed provided false information regarding its flag and possible insurance coverage. The vessel which is laden with Russian oil is being tracked as it makes its outbound transit but so far Denmark has taken no action against the vessel.
The tanker which appears to be identifying with the name Marathon, or previously Udaya, (IMO 9288746) was first identified as a suspect vessel on its inbound transit to the Baltic on June 10. According to the outlet Danwatch, the Danish patrol ship Freja approached the vessel, but there was no apparent attempt to intercept or stop the tanker. The Danish patrol boat was sailing alongside but changed course away from the tanker.
The Danish Maritime Authority told Danwatch, “During radio contact with the Defense Command, the Udaya/Marathon reported that it was flying the Comoros flag. However, during subsequent checks with the Comoros authorities, we received confirmation that the vessel was not registered in the Comoros registry.”
The vessel’s AIS signal shows it departed Primorsk, Russia on June 16 with a declared destination of the Suez Canal. Tracking data from today, June 19, shows it is transiting the Danish straits at a speed of 12 knots. The AIS signal warns its navigational status is constrained by draft. The reports suggest the vessel is carrying 100,000 tons of Russian oil likely bound for India.
Denmark, like the other nations of the region, remains on high alert monitoring shadow fleet tankers. Estonia and Germany have challenged some of the tankers based on suspicious activity or likely false flag operations while Denmark has said it also would consider intervention. Speaking on Danish TV 2 Foreign Minister Lars Løkke Rasmussen at the end of May called for tightening controls on the shadow tankers. He said legally it was difficult but that “I do not rule out the possibility that we may have to intervene to a greater extent. If you cannot show the correct insurance papers and do not have a flag state, then it is legitimate to intervene,” said Rasmussen. In February 2025, Denmark reported it would be increasing its inspection program targeting tankers.
This tanker is an example of the worst of the shadow fleet. In addition to the accusation that it is sailing without a flag state, the vessel has reported at least three other flags (Djibouti, Gabon, and St. Kitts and Nevis) in the past three years since 2022. The ship was sanctioned by the UK at the end of 2024, and the EU, Canada, and Switzerland in early 2025.
The tanker has been tied to repeated calls in Russia, India, Lebanon, Egypt, and other ports. Equasis lists the flag as unknown and since March 2024 ownership associated with a company in Mauritius. Management is listed in India.
The tanker according to Equasis had not undergone a Port State inspection between July 2022 and April 2025. Its most recent inspection was in Russia, where the authorities cited it for a lack of fire patrols and issues with its inflatable liferafts. The ship was not given a detention.
Danwatch reports this is at least the second vessel Denmark recently identified as being stateless sailing through its waters. The Danish Maritime Authority did not respond to media inquiries regarding the outbound passage of the tanker.
Top photo by L-BBE in 2013 -- CC BY 3.0 DEED