From concept to capability: Advancing NATO’s maritime autonomy

Testing where it matters

REPMUS, short for Robotic Experimentation and Prototyping using maritime uncrewed systems, is one of the most relevant arenas for testing maritime autonomy in realistic operational environments. Held in Tróia, Portugal, together with BOLD MACHINA, the exercise brings together allied forces, industry and technology providers to explore how uncrewed and autonomous systems perform under real mission pressure.

For us, taking part in REPMUS is important because the challenges at sea are growing in both scale and complexity. The ocean covers more than 70% of the Earth’s surface and plays a central role in global security, trade, energy infrastructure and climate monitoring. At the same time, traditional crewed operations can be expensive, exposed and difficult to maintain across large or contested maritime areas.

This is where autonomous sea drones provide real operational value. By extending reach, carrying sensors and collecting data without placing people directly in exposed situations, they can support safer, smarter and more persistent operations at sea.

In this context, autonomy is not only a technology question. It is part of a broader security picture, connected to geopolitical stability, strategic trust and the protection of the infrastructure society depends on every day.

Our role  in Tróia

During the exercise, we deployed our sea drones Mariner, Mariner X and Sentry in scenarios connected to maritime security, coastal protection and operational awareness. Our work focused on testing autonomous sea drones in realistic maritime scenarios, supporting situational awareness across complex waters, working with acoustic payloads and sensor systems, and exploring how uncrewed systems can reduce risk for people while strengthening mission capability.

One of the missions focused on subsea detection and tracking of underwater activity. For this scenario, Mariner X operated with a thin-line towed acoustic array, supporting passive acoustic sensing in a real maritime environment.

The mission demonstrated how an uncrewed surface vessel can act as a flexible sensor platform: moving into position, towing the array, collecting acoustic data and repositioning as the operation develops. In this way, Mariner X contributed to a broader underwater awareness setup while reducing the need to keep people directly exposed at sea.

For us, this is where autonomy becomes especially valuable. The vessel is not only operating on its own; it is carrying the sensors, supporting the data collection and becoming part of a larger operational chain with partners, operators and allied forces.

Sentry also took on demanding roles during the exercise. Sentry is our compact high-speed target sea drone, designed to support realistic training and test scenarios. For our team, this provided valuable insight into how compact uncrewed systems can support training, operational awareness and decision-making in realistic conditions.

Together, these activities reinforced one of the most important lessons from REPMUS: the value of autonomy is not found in the platform alone. It comes from how the platform works with sensors, operators, data flows, mission requirements and partner systems.

Lessons learned

A sea drone is only one part of the operational chain. The vessel matters, but so do the payload, the operator interface, the data flow and the people using the system.

That is why exercises like REPMUS are so valuable. They create the conditions to test collaboration in practice, not only in theory. In the field, under operational pressure, teams learn what works, what needs to be improved and how different systems can support each other.

For autonomy to become trusted operational capability, it must work as part of a wider system. It must connect with existing procedures, partner technologies and real mission needs. When these elements come together, autonomous systems become more than individual platforms. They become part of the way maritime operations are planned, understood and carried out.

Team thoughts from the exercise

REPMUS was  a strong reminder of why this work matters. Testing technology in this environment is not only about proving performance. It is about working with people who share the same goal: improving maritime preparedness and helping protect society.

That perspective captures something essential about REPMUS. Collaboration is not just a way of working during the exercise. It becomes part of the capability itself.

When naval forces, technology providers and industry partners test together, they build more than technical understanding. They build trust. They learn how systems behave in shared environments, how information moves between people and platforms, and how autonomous technology can support real operational decisions.

From testing to trust

As hybrid threats increase and the maritime domain becomes more demanding, the need for persistent awareness and stronger protection continues to grow. Sovereign waters, ports, subsea energy infrastructure, data cables and critical maritime routes all require systems that can stay in the field, collect high-quality data and support decision-makers with reliable information.

At REPMUS 2026, Maritime Robotics tested how autonomous sea drones can contribute to that need. The exercise gave us valuable operational insight, strengthened collaboration with partners and customers, and reinforced a clear principle: maritime autonomy is not only about technology. It is about enabling people to operate safer, smarter and with greater confidence at sea.

Thanks to our hard-working team in Tróia and everyone who joined us in the field. Putting tech to the test in real maritime conditions is how we turn ideas into action—giving NATO forces the reliable, uncrewed capability they need to stay ahead.