Portugal hosted a NATO-backed maritime exercise this autumn that brought thousands of personnel and hundreds of uncrewed vessels and other systems together to test new technologies at sea.
REPMUS 2026 ran from 31 August to 25 September and included the integration and assessment of uncrewed maritime systems — remotely operated or autonomous vehicles designed to operate on, above or below the sea, NATO announced on Thursday.
More than 3,700 participants took part, alongside 300 unmanned systems, 60 research and development companies and representatives from 36 navies.
The exercise was led by the Portuguese Navy, working with the Faculty of Engineering of the University of Porto, NATO’s Science and Technology Organization Centre for Maritime Research and Experimentation, NATO’s Joint Capability Group Maritime Unmanned Systems and the European Defence Agency.
Innovators from the UK, Finland, Sweden and other NATO Allies also took part in trials held in Troia.
Task Force X-Arctic tested alongside maritime trials
One of the activities assessed during the exercise was Task Force X-Arctic, a programme led by NATO’s Allied Command Transformation together with the Centre for Maritime Research and Experimentation, NATO said.
Task Force X-Arctic looks at using networked uncrewed systems to provide “situational awareness” — information about what is happening in an area — across the North Atlantic, the Arctic and the High North.
REPMUS 2026 was used to assess elements of the programme designed to integrate systems at scale, ahead of a further trial planned in Norway later this year.
