REPMUS 2026 Puts NATO Uncrewed Maritime Systems to the Test in Portugal

8 October 2026
Edited By: Lauren Ernst

From August 31 to September 25, 2026, Portugal hosted REPMUS 2026, a large-scale exercise which included integrating and assessing uncrewed maritime systems. It involved more than 3,700 participants, 300 unmanned systems, 60 research and development companies, and representatives of 36 navies. Uncrewed systems offer new ways for NATO to maintain a credible and persistent presence, even in remote locations, helping enhance deterrence and defense.

(Image credit: NATO)

REPMUS 2026 was led by the Portuguese Navy in coordination with the Faculty of Engineering of the University of Porto, the NATO Science and Technology Organization (STO) Centre for Maritime Research and Experimentation (CMRE), NATO Joint Capability Group Maritime Unmanned Systems, and the European Defence Agency. Defense innovators from the United Kingdom, Finland, Sweden, and other NATO Allies also took part in the exercise in Troia to test their technologies.

Task Force X-Arctic—led by NATO’s Allied Command Transformation and the CMRE—was one of the activities under review. Task Force X-Arctic is about how networked uncrewed systems can deliver situational awareness across the North Atlantic, the Arctic, and the High North. REPMUS 2026 helped assess TFX-Arctic’s mission-engineering layer as well as its ‘connectivity backbone’ to integrate systems at scale. This is ahead of a trial taking place in Norway at the end of this year.