TROIA, Portugal — Representatives from the Ukrainian navy participated in NATO’s largest unmanned maritime systems exercise this month, simulating the opposing force to test the capabilities of two dozen allied countries in scenarios inspired by frontline action.
Ukraine was one of 24 countries involved in the Portugal-led military exercise, REPMUS 2025, conducted from September 1-26. The focus of the exercise was to evaluate hundreds of autonomous systems for naval applications.
Captain Valter de Bulha Almeida of the Portuguese Navy addressed reporters, stating that Ukrainian forces assumed the role of the adversarial “red team.” The scenarios were informed by their experiences on the battlefield in defending against Russian forces. He emphasized the importance of developing tactics and learning from Ukraine’s frontline experiences.
The Captain noted that Ukrainian unmanned surface vessels participated, but did not provide further details due to security concerns. For the exercise, the red team, which included Ukraine, had a total of 61 drones, 57 unmanned surface vehicles (USVs), and one unmanned ground vehicle.
Images claiming to show an upgraded variant of the Magura V7 drone boat, developed by the Ukrainian state-owned company SpetsTechnoExport (STE), were initially shared by the Portuguese defense blog Defence360. When inquired about the craft’s involvement in the exercise, a STE representative declined to comment but referenced a report from the Ukrainian media outlet Militarnyi discussing the naval drone’s presence in Portugal.
The Magura naval drones have been extensively documented throughout the ongoing conflict. At the DSEI trade show in London in 2023, STE disclosed that the Magura V5 was “the world’s first maritime drone with public video confirmation of hitting legitimate targets, including Russian warships.” The Magura V7, in its operational setup, weighs approximately 3,400 kilograms and is capable of covering distances of up to 1,500 kilometers.
Naval drones are gaining prevalence within European militaries. In 2023, the Portuguese Navy established its inaugural squadron-sized drone unit, inspired directly by the dynamic on the Ukrainian battlefield. Known as X31, this unit operates under the naval command and focuses on testing and operating aerial, surface, and subsea unmanned systems, while contributing to the development and coordination of drone warfare doctrine.
Some systems recently trialed by the X31 unit were present at REPMUS, such as the Trator Do Mar, developed by the Portuguese Navy’s Unmanned Vehicles Operational Experimentation Cell (CEOV). This USV is designed for maritime domain awareness and seabed mapping but is not yet operational.
Notably, this year’s NATO exercise included daily jamming trials conducted between 5-6 p.m. to simulate combat-like environments for the exercise drones.
Elisabeth Gosselin-Malo is a Europe correspondent for Defense News, covering military procurement, international security, and specializing in aviation-related reporting from Milan, Italy.
