The operations presented collaboration between uncrewed surface vessels and autonomous underwater vehicles (AUVs) to support mine countermeasures and rapid environmental assessment in a safer, precise, and more efficient way.
Two Uncrewed Systems Working Together
REPMUS 2026 took place from August 31–September 25 in the areas of Tróia and Sesimbra, Portugal. The exercise brought together naval forces, industry partners, and technology providers to test maritime uncrewed systems in realistic operational conditions.
During the exercise, Mariner X operated on the surface as a mobile command hub, communication bridge, and positioning reference for the CORAX 600 AUV below. This helped address one of the key challenges in underwater operations: radio signals such as GNSS, Wifi, and LTE do not penetrate water. As a result, underwater vehicles depend on acoustic communication and positioning support from the surface.
The Mariner X corrects the AUV’s position acoustically and relays status, contacts, and re-tasking to shore.
By following the AUV’s survey pattern from above, Mariner X supported CORAX 600 with acoustic positioning updates and relayed status, contact reports, and re-tasking information between the AUV and operators ashore.
Supporting Mine Countermeasures and Environmental Assessment
The result was a fully uncrewed surface–subsea pair designed to support more efficient mine countermeasure operations without the need for a mother ship or divers near a suspected mine.
For mine countermeasure missions, CORAX 600 surveys the seabed using sidescan sonar and can move close to possible contacts for optical classification. Mariner X then helps stream the resulting contact reports to operators positioned safely outside the minefield.
The same surface–subsea pairing can also support rapid environmental assessment by mapping bathymetry and seabed conditions ahead of naval deployments or offshore infrastructure work.
Keeping People Away from Hazardous Areas
The demonstration highlighted three key operational advantages: reducing risk by keeping people away from hazardous areas, improving precision navigation through continuous surface-to-subsea positioning support, and increasing deployability by using a compact system that does not require a purpose-built vessel.
The system can be trailered, packaged, and launched from a small slipway, making it deployable by a small team and well suited for operations where speed, safety, and flexibility are essential.
From Mongstad to Tróia
The deployment at REPMUS followed earlier joint testing by Skarv Technologies and Maritime Robotics at the IXES exercise in Mongstad, Norway. Together, the two deployments show how the same combined capability can support both national infrastructure protection and allied expeditionary mine countermeasure operations.
By bridging surface connectivity with subsea data gathering, the collaboration demonstrates how uncrewed maritime systems can make maritime security operations safer, smarter, and more scalable.
