Dutch regional outlet Omroep Gelderland reported that it managed to follow the HNLMS Evertsen in real time after slipping a Bluetooth tracker into military mail sent to the vessel. The frigate is currently operating as part of a carrier strike group centered on France’s Charles de Gaulle in the Mediterranean.
The device was only uncovered during onboard mail sorting—after the broadcaster had already monitored the ship’s movements for roughly a full day. In response, the Ministry of Defence of the Netherlands said it is reviewing procedures and taking corrective steps.
The episode follows an earlier report by Le Monde, which revealed that data from the fitness app Strava exposed the activity of a French officer jogging laps on the Charles de Gaulle while it was at sea.
According to Rowin Jansen of Radboud University, such vulnerabilities highlight serious risks. He noted that while delayed satellite imagery exists for security reasons, real-time tracking tools could be exploited, potentially allowing hostile actors to pinpoint naval assets.
To carry out the test, the broadcaster mailed a tracker—commonly used to locate personal items—using instructions provided online by the defence ministry. Although parcels are typically scanned for hazardous materials, the team observed that envelopes are not always checked, allowing the device—concealed in a postcard—to pass through undetected.
Retired Lieutenant General Mart de Kruif stressed that evolving threats demand a shift in mindset, arguing that relying solely on existing procedures is no longer sufficient in a high-risk security environment.
Tracking data showed the device traveling from the naval base in Den Helder to Eindhoven Airport, then onward to Heraklion in Crete, where visual confirmation placed the Evertsen docked. After departing on March 27, the ship’s route could be followed westward along Crete before turning east. The signal eventually dropped near Cyprus after about 24 hours.
Following the incident, the defence ministry has tightened mailing rules—banning battery-powered greeting cards for the vessel—and is reassessing broader mail-handling policies. While officials stated the tracking did not create an immediate operational threat, the case has prompted further scrutiny.
Defence Minister Dilan Yeşilgöz has since briefed parliament on the matter, according to the broadcaster.
