REPMUS, or Robotic Experimentation and Prototyping using Maritime Unmanned Systems, is hosted by the Portuguese Navy alongside EDA and NATO and is described by the agency as Europe’s largest exercise of its kind. The demonstration is intended to support the development of a fully classified MARSUR network operating at EU Secret level by 2028.
Jürgen Scraback, Head of the Maritime Domain at EDA, said the REPMUS results marked “the first time this level of multi-domain integration has been proven live, rather than just on paper.” He said the test also represented a significant step towards the planned classified network and addressed another EU capability gap under the Readiness 2030 agenda.
MARSUR is a federated network developed under EDA’s auspices to provide participating European countries with a shared, real-time picture of maritime activity. It is designed to complement NATO’s maritime surveillance architecture by combining data from EU navies, radar, satellites and open-source feeds.
During REPMUS, MARSUR used a data-exchange standard implemented for the exercise to ingest information made available by participating nations and systems. The network processed data originating from unmanned systems as well as national and NATO sources and redistributed it within MARSUR.
Many of the 23 participating EU nations also tested standard operating procedures for the network and ran national scenarios reflecting individual maritime security priorities. These included the protection of underwater infrastructure and the monitoring of so-called shadow fleet vessels used to evade sanctions.
Portugal’s President António José Seguro received a briefing on MARSUR during the exercise, while Sweden’s Chief of Navy, Rear Admiral Johan Norlén, was also briefed. EDA said the high-level attention reflected growing interest in the network’s capabilities.
The REPMUS results strengthen the case for a funding request submitted under an EU Defence Project of Common Interest to upgrade MARSUR to EU Secret classification. The proposal would modernise 18 network nodes and integrate the system with the European External Action Service’s secure operational network.
Subject to European Council approval later in 2026, work would begin in 2027 and the fully classified network is expected to become operational in 2028. MARSUR currently operates at an unclassified, protected level and, although it is technically ready for EU Restricted classification, the decision was taken to pursue EU Secret level directly.
Source: European Defence Agency
