US and Denmark to Deploy Voyager Spy Drone Fleet Off Estonia’s Baltic Coast

The United States and Denmark are set to deploy a fleet of Voyager autonomous sea drones off the coast of Estonia in June 2025, aimed at monitoring maritime activities in the Baltic Sea, according to Defense News, which cited NATO sources. This initiative is part of NATO’s Operation Baltic Sentry, designed to enhance control over the strategically vital region amid escalating tensions with Russia.

The Voyager drones, developed by the American company Saildrone, are unmanned sailing vessels powered by solar panels. They can operate autonomously for up to 12 months without returning to port and are tasked with gathering data on various maritime factors, including vessel movements, the condition of underwater infrastructure, and potential threats such as sabotage. The data collected is analyzed using artificial intelligence, ensuring high accuracy and rapid processing. According to The Defense Post, each Voyager drone can carry up to 250 kg of equipment, including sonars, cameras, and sensors for detecting chemicals, making them versatile reconnaissance tools.

This drone deployment follows a series of incidents in the Baltic Sea, including damage to underwater communications cables between Estonia and Finland in December 2024, which both countries described as “possible sabotage.” Suspicion was directed at the Chinese vessel Yi Peng 3, which was in proximity to the cables at the time. Additionally, in March 2025, the Associated Press reported that 40 U.S. Marines, along with drones, were sent to Finland to participate in “Baltic Sentry,” and now the American and Danish Voyager drones will join this effort.

Estonia, Latvia, and Lithuania, situated on NATO’s eastern flank, are actively advocating for measures to bolster security in the Baltic Sea. Estonian Foreign Minister Margus Tsahkna commented on the program, stating that “protecting critical infrastructure is a priority for countries in the region.” In line with this initiative, the Baltic states are enhancing their naval capabilities, with Lithuania acquiring two attack boats, Poland constructing frigates, and Estonia planning to purchase up to 12 new ships.