Denmark Deploys Surface Drones for Baltic Sea Surveillance

Denmark has initiated the use of four autonomous surface drones, known as Saildrone Voyagers, for maritime surveillance in the North and Baltic Seas. This strategic move aims to enhance security in Danish waters and prevent potential sabotage incidents, particularly following recent attacks on undersea infrastructure.

The deployment of these drones, which are equipped with both wind and electric propulsion systems, is currently slated for a three-month period. They will monitor Danish maritime territories while bolstering NATO's vigilance in the ongoing context of heightened geopolitical tensions stemming from Russia's invasion of Ukraine.

The need for increased surveillance has been underscored by recent acts of sabotage targeting undersea cables, including the notorious Nord Stream pipeline incidents. On Monday, two of the Voyager drones set sail from Køge Marina, located approximately 40 kilometers south of Copenhagen, following the earlier launch of two additional drones on July 6.

Each Voyager drone is approximately 10 meters long and features a fixed sail that can be adjusted by an electric motor to optimize wind utilization for propulsion. This hybrid design allows for extended operational durations, as the drones can conserve energy by relying on wind power rather than solely on their motors. In situations where wind conditions are insufficient for navigation, an electric motor powered by a solar-charged battery will engage to maintain maneuverability.

Equipped with a suite of autonomous systems, the Voyager drones are designed for independent military reconnaissance missions. These systems include advanced navigation and control technologies, as well as various sensors such as radar, infrared cameras, optical devices, sonar, and acoustic sensors. The data collected by these drones will be analyzed using machine learning and artificial intelligence to provide a comprehensive assessment of surface and underwater activity. This capability enables early identification of potentially hostile vessels and operations, allowing for timely communication with military command centers for appropriate responses.

The initial focus of these surveillance efforts is the protection of undersea cables within Danish waters. Since 2023, there has been a notable increase in incidents affecting maritime infrastructure. The most recent disruption occurred in January 2025 when a fiber optic connection between Latvia and the Swedish island of Gotland was severed. In total, there have been damages to at least eleven undersea cables over the past two years, highlighting the urgency of the situation.

Prior to these incidents, the destruction of the Nord Stream pipelines in 2022 raised significant concerns about infrastructure security. Investigations have suggested that many of these incidents may be attributed to acts of sabotage by hostile entities, with some reports indicating involvement from Russian-operated vessels, often referred to as the shadow fleet, which consists of aging oil tankers with unclear ownership.

The four Voyager drones will operate in conjunction with other monitoring initiatives, including conventional ships and aerial drones, to detect suspicious maritime movements in the North and Baltic Seas. Their autonomous nature allows for more sustainable and cost-effective operations compared to manned vessels.