SUMMARY
MARSUR III is the EDA Cat. B project that has delivered the next‑generation technical solution, both system and network components, for the automated exchange of maritime surveillance information between the navies of the 16 contributing Member States. The project is linked to the wider MARSUR initiative, which is regulated by a Ministerial‑level Technical Arrangement and brings together 23 European nations committed to sharing information in the maritime domain. Of these 23 participants, 16 currently benefit from the MARSUR III surveillance system, which enables automated information exchange through the newly developed next‑generation information exchange system.
MARSUR III provides the operational backbone supporting secure maritime information sharing not only between European navies, but also in direct support of CSDP missions and operations. The system is accessible to EEAS structures, specifically the MAICC, and will soon be extended to the MPCC and the EU‑level headquarters through an upcoming dedicated EDA–EEAS bilateral arrangement. This will enable these bodies not only to access the platform but also to contribute directly to the shared information environment. By providing a common Recognised Maritime Picture (RMP) for national authorities, CSDP missions, and EU operations, MARSUR III significantly enhances European maritime situational awareness and operational coordination. This way, MARSUR III is designed to evolve into the EU Maritime Surveillance Network, providing the technological backbone for addressing the Maritime Domain Awareness (MDA) priority set out in the EU Capability Development Priorities (CDP) 2023.
Why MARSUR III matters
- Provides secure, real-time maritime information exchange among European navies
- Strengthens Europe’s shared RMP for operations and missions
- Supports EU Coordinated Maritime Presences and CSDP missions and operations
- Reinforces EU–NATO interoperability and cooperation in maritime security
- Strong European footprint, leveraging state-of-the-art technologies
A secure and scalable maritime information network
MARSUR III delivers a decentralised, peer-to-peer architecture connecting national Maritime Operations Centres (MOCs), EU Operational Headquarters and SatCen nodes through encrypted VPN networks. The system supports automated data exchange, integrates with national surveillance systems, and can also operate as a stand-alone capability through the MARSUR User Interface.
By enabling the fusion of national and satellite data into a coherent RMP, MARSUR III significantly enhances maritime situational awareness across surface and subsurface domains and improves operational decision-making in live operational environments.
Classified information exchange and interoperability
The next milestone for MARSUR III is the implementation of an EU SECRET layer, which will facilitate the secure management and exchange of classified maritime surveillance data, ensuring comprehensive situational awareness at the EU level. . This classified layer will utilize fast-track integration with the EU Operations Wide Area Network (EU OPS WAN) to support secure cross-domain information exchange. Furthermore, it will ensure seamless interoperability with the Common Information Sharing Environment (CISE) for data at lower classification levels.
MARSUR III is designed in line with NATO Federated Mission Networking standards. Upcoming testing activities, including CWIX 2026 (classified enclave) and REPMUS 26, will further validate interoperability with NATO systems, Member States’ legacy architectures, and emerging underwater and unmanned systems. This interoperability reinforces Europe’s ability to act autonomously while remaining fully connected with its transatlantic partners and other multinational maritime security frameworks.
Contribution to European maritime security and border defence
MARSUR III directly contributes to the implementation of EDA Maritime Priority Capability Area objectives and supports EU Capability Development Plan priorities on Maritime Domain Awareness and seabed security. By enabling multi-domain maritime surveillance and rapid information-sharing across Member States, the project strengthens monitoring of Europe’s maritime borders, particularly in strategically sensitive regions such as the Eastern Flank.
Beyond a technical network, MARSUR III is a cornerstone capability for European maritime cooperation, enabling faster decision-making, enhanced operational coordination, and a more resilient European maritime security architecture.
Key Capabilities
MARSUR III provides a secure and scalable network based on a decentralised peer-to-peer architecture that connects national Maritime Operations Centres (MOCs), EU Operational Headquarters, and SatCen nodes through encrypted Virtual Private Network (VPN). It enables multi-source data fusion by integrating national surveillance systems and satellite information into a coherent RMP across both surface and subsurface domains. In addition, it offers flexible integration, operating either in conjunction with national systems or as a stand-alone capability through the MARSUR User Interface.
Strategic Impacts
- Strengthens EU strategic autonomy
- Enhances the protection of critical maritime and seabed infrastructure
- Improves Europe’s ability to anticipate, detect and respond to maritime threats and crises
- Enhances maritime situational awareness across Europe’s sea borders
- Supports EU Coordinated Maritime Presences and CSDP missions
- Enables faster operational decision‑making through real-time information sharing
- Strengthens Europe’s comprehensive maritime border defence and security architecture
Operational Demonstration: MARSUR III in Action
In February 2025, the MARSUR III Operational Capability Demonstration at EUNAVFOR MED IRINI OHQ in Rome tested its performance in countering illegal arms trafficking to and from Libya and disrupting human smuggling and trafficking networks.
The demonstration confirmed MARSUR III’s ability to fuse real-time data from ships, national MOCs, and satellites into a single, coherent RMP. It also proved MARSUR’s value in protecting critical seabed and underwater infrastructure, issuing alerts when vessels behave suspiciously over sensitive areas such as pipelines or cables.
The exercise showed that MARSUR is not only a tool for navies, but a true operational enabler for EU CSDP missions and operations. It can provide RMP support to any future EU Operation Headquarters, ashore or afloat.
A Key Enabler of the 2023 Capability Development Plan
MARSUR III plays a central role in implementing the 2023 EU Capability Development Plan (CDP) and its Priority Implementation Roadmap (PIR) for Maritime Domain Awareness (MDA). It directly contributes to the EU’s maritime security ambitions by:
- Delivering the Next-Generation Maritime Situational Awareness capability;
- Enabling cooperative use of multi-domain data sources — from satellites and manned aircraft to drones, sensors, and underwater systems;
- Acting as the EU defence layer of the Common Information Sharing Environment (CISE) to facilitate civil-military information sharing;
- Preparing the roll-out of a classified layer (EU RESTRICTED, with future upgrade to EU SECRET) integrated into the EU OPS WAN;
Preparing the Future
Looking ahead, MARSUR III is set to become the central backbone of the European surveillance network, establishing a seamless 'seabed-to-space' operational environment. By integrating a multi-domain array of manned and unmanned sources—including satellites, UxV, underwater sensors, and coastal radars—the network will ingest and distribute a unified data stream to ensure Europe is prepared to predict, assess, and react to threats in a federated manner, both promptly and effectively.
Central to this evolution is the forthcoming implementation of an EU SECRET layer. This capability will enable a comprehensive and classified Recognised Maritime Picture (RMP), providing the secure foundation necessary for high-level and operational decision-making.
Leveraging real-time data, video streaming from maritime and aerial assets, and future AI-enabled analytics, MARSUR III will fully integrate into the EU OPS WAN. By delivering this secure, shared RMP, MARSUR III empowers European navies to operate faster and smarter, protecting EU interests wherever they are at stake.