# EU's MARSUR network exchanges data live with NATO systems at REPMUS

- Source: Nordic Defence Sector (https://nordicdefencesector.com)
- Canonical URL: https://nordicdefencesector.com/en/article/eus-marsur-network-exchanges-data-live-with-nato-systems-at-repmus
- Published: 2026-09-25
- Author: Daniel Trangeled
- Type: News · Section: Maritime · Country: international
- Language: en (original)
- Also available in: de (https://nordicdefencesector.com/de/article/eus-marsur-network-exchanges-data-live-with-nato-systems-at-repmus.md), dk (https://nordicdefencesector.com/dk/article/eus-marsur-network-exchanges-data-live-with-nato-systems-at-repmus.md), es (https://nordicdefencesector.com/es/article/eus-marsur-network-exchanges-data-live-with-nato-systems-at-repmus.md), fi (https://nordicdefencesector.com/fi/article/eus-marsur-network-exchanges-data-live-with-nato-systems-at-repmus.md), fr (https://nordicdefencesector.com/fr/article/eus-marsur-network-exchanges-data-live-with-nato-systems-at-repmus.md), it (https://nordicdefencesector.com/it/article/eus-marsur-network-exchanges-data-live-with-nato-systems-at-repmus.md), no (https://nordicdefencesector.com/no/article/eus-marsur-network-exchanges-data-live-with-nato-systems-at-repmus.md), pl (https://nordicdefencesector.com/pl/article/eus-marsur-network-exchanges-data-live-with-nato-systems-at-repmus.md), sv (https://nordicdefencesector.com/sv/article/eus-marsur-network-exchanges-data-live-with-nato-systems-at-repmus.md)
- Primary source: https://eda.europa.eu/news-and-events/news/2026/09/23/eda-s-marsur--eu%27s-eyes-at-sea-talk-to-national-and-nato-systems-in-real-time
- Tags: european defence agency, eda, repmus, nato, marsur, sverige, portuguese armed forces, european external action service, eu secret, eu, portugal, sweden, shadow fleet, unmanned systems, maritime surveillance

> EDA demonstrated at the REPMUS exercise in Portugal that MARSUR, the EU's maritime surveillance network, can exchange real-time data with national and NATO systems, marking the first live proof of this level of multi-domain integration. A funding request has now been submitted to upgrade MARSUR to EU Secret classification, with a fully classified network expected to be operational by 2028.

![Participants to the REPMUS exercise monitoring activity at sea in the control room using MARSUR](https://imagedelivery.net/XO8UY-c6-LfWgEjQsN8IQw/b03d017c-53ec-444e-bddd-6dd2c3c58600/public)
*Participants to the REPMUS exercise monitoring activity at sea in the control room using MARSUR · EDA*

**The European Defence Agency (EDA) [has shown](https://eda.europa.eu/news-and-events/news/2026/09/23/eda-s-marsur--eu's-eyes-at-sea-talk-to-national-and-nato-systems-in-real-time) that MARSUR, the EU's maritime surveillance network, can exchange data in real time with national command systems and NATO. The test took place at the REPMUS exercise off Portugal in September.**

According to EDA, MARSUR took in data from unmanned systems and from national and NATO sources. It then shared that data across its network. Many of the 23 participating EU nations also ran their own scenarios. These included protecting underwater infrastructure and monitoring shadow fleet vessels used to evade sanctions, EDA said.

— The first time this level of multi-domain integration has been proven live, rather than just on paper, said Jürgen Scraback, head of the maritime domain at EDA, about the REPMUS results.

Sweden's Chief of Navy, Rear Admiral Johan Norlén, was briefed on the system during the exercise. Sweden is also [testing](https://nordicdefencesector.com/en/article/sweden-brings-28-unmanned-systems-to-natos-repmus-exercise) 28 unmanned systems at REPMUS, as previously reported by NDS.

According to EDA, a funding request has been submitted to upgrade MARSUR from its current protected, unclassified level to EU Secret. The plan would modernise 18 network nodes. It would also connect MARSUR to the European External Action Service's secure network. Subject to European Council approval later this year, work would begin in 2027. EDA says a fully classified network would be operational by 2028.

## FAQ

**What did EDA demonstrate with MARSUR during the REPMUS exercise?**

EDA demonstrated that MARSUR, the EU's maritime surveillance network, can exchange data live with national command systems and NATO. The test occurred at the REPMUS exercise off Portugal in September, taking in data from unmanned systems and national and NATO sources. Jürgen Scraback called it the first live proof of this integration. Last fact-checked: 2026-09-25.

**What upgrade is planned for the MARSUR network and when would it be completed?**

A funding request has been submitted to upgrade MARSUR from protected, unclassified level to EU Secret, modernising 18 network nodes and connecting to the European External Action Service's secure network. Pending European Council approval, work would start in 2027, with a fully classified network operational by 2028. Last fact-checked: 2026-09-25.

**Which scenarios did EU nations run during the REPMUS exercise involving MARSUR?**

Among the 23 participating EU nations, scenarios included protecting underwater infrastructure and monitoring shadow fleet vessels used to evade sanctions, according to EDA. These national exercises ran alongside the MARSUR data-sharing test at REPMUS off Portugal in September. Last fact-checked: 2026-09-25.

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