A Day Without GPS: Denmark Reports Navigation Disruptions for Ships in Baltic Sea

Denmark has noted a record number and duration of GPS disruptions in the Baltic Sea.

This was reported by the local news outlet DR.

Jens Nielsen, captain of the cargo ship Saturn, reports that communication problems are occurring in the southeastern part of the Baltic Sea.

“On July 29, we lost signal for about a day between Gdańsk and southern Gotland. During our last trip from Gdańsk back to Hundested, we had no signal all the way to Bornholm,” the captain said.

Jens Nielsen noted that GPS issues in the area had previously lasted an average of 15–20 minutes per day, but recently the situation has become worse than ever.

The Danish Tein measurement station on the island of Bornholm—a long-term monitoring site—recorded 30 instances of GPS jamming and spoofing. By comparison, the total number of incidents last year was 16.

The source of the GPS interference has not yet been officially disclosed. Søren Reime Larsen, a researcher at DTU Space specializing in GPS disruptions, notes that such activity is linked to Russia’s attempts to defend itself against Ukrainian UAVs.

Finland reported similar signal jamming in the Archipelago Sea and the Åland Sea on May 26, which supports the hypothesis that Russian electronic warfare is at work.

“When we receive these measurements from Bornholm, I don’t think this is a deliberate attack on Bornholm’s infrastructure,” the researcher notes.

Authorities in many European countries—including Denmark—accuse Russia of disrupting navigation systems in the Baltic Sea. They expressed their concerns about the threat to shipping in the area in an open letter.

It is likely that Russia is using the Murmansk BN electronic warfare system, located in Kaliningrad, to interfere with the flight paths of Ukrainian drones attacking Russian territory.