Denmark Deploys Uncrewed “Voyager” Sailboats for Maritime Surveillance Amid Rising Baltic Tensions

Four uncrewed robotic sailboats, known as “Voyagers,” have been deployed by Denmark’s armed forces for a three-month operational trial aimed at boosting surveillance in Danish and NATO waters in the Baltic and North Seas, amid rising maritime tensions and concerns about sabotage.

The 10-meter (30-foot) long vessels, developed by California-based company Saildrone, were launched Monday from Koge Marina, about 40 kilometers (25 miles) south of Copenhagen. Two Voyagers have already joined a NATO patrol on June 6. These autonomous, wind- and solar-powered vessels can remain at sea for months and are equipped with advanced sensor systems, including radar, infrared and optical cameras, sonar, and acoustic monitoring.

Saildrone founder and CEO Richard Jenkins described the vessels as “trucks” carrying sensors, enhanced by machine learning and artificial intelligence, to provide a comprehensive surface and subsurface picture within a 20 to 30 mile (30 to 50 kilometer) range in the open ocean. Jenkins highlighted the vessels’ role in detecting often-overlooked maritime threats such as undersea cable damage, illegal fishing, and smuggling.

“They’re going to cruise Danish waters, and then later they’re going to join up with the two that are on (the) NATO exercise,” said Lt. Gen. Kim Jørgensen, director of Danish National Armaments at the Defense Ministry. “Then they’ll move from area to area within the Danish waters.”

The trial follows a series of incidents targeting undersea infrastructure, including the 2022 Nord Stream pipeline explosions and the severing of at least 11 undersea cables since late 2023. In January, a fiber-optic link between Latvia and Sweden’s Gotland island was disrupted.

Amid these threats, NATO is developing a layered maritime surveillance system integrating uncrewed surface vessels like the Voyagers with manned naval ships, satellites, and seabed sensors. The goal is to maintain constant and cost-effective monitoring of maritime activity.

“The challenge is that you basically need to be on the water all the time, and it’s humongously expensive," said Peter Viggo Jakobsen of the Royal Danish Defence College. “We’re trying to put together a layered system that will enable us to keep constant monitoring of potential threats, but at a much cheaper level than before.”

Some of the recent disruptions have been attributed to Russia’s so-called shadow fleet — aging tankers operating under obscure ownership structures to bypass international sanctions. One such vessel, the *Eagle S*, was seized by Finnish authorities in December for allegedly damaging a power cable between Finland and Estonia.

The trial also unfolds amid lingering geopolitical friction, including past remarks by U.S. President Donald Trump suggesting a military option to acquire Greenland, a semiautonomous Danish territory. Jenkins said Saildrone had planned its Danish operation before Trump’s reelection and declined to comment on the Greenland issue, stating the company remains apolitical.