Skarv Technologies and Maritime Robotics prove uncrewed surface–subsea operations at REPMUS 2026
Skarv Technologies and Maritime Robotics demonstrated coordinated uncrewed surface and subsea operations during REPMUS 2026 in Portugal, pairing Maritime Robotics’ Mariner X USV with Skarv Technologies’ CORAX 600 AUV.
The operations presented collaboration between uncrewed surface vessels and autonomous underwater vehicles 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 31 August to 25 September 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, Wi-Fi 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.
Mariner X sea drone (USV) during REPMUS 2026.
Supporting mine countermeasures (MCM) and environmental assessment (EA)
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.
The CORAX 600 AUV system. Image credit: Skarv Technologies 2026.
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.
Left: Mariner X Seadrone (USV) on the water, following the CORAX 600 while the AUV runs a camera mission. Right: Close-range optical image of a practice target on the seabed, with a detail of the marking on the object. The image is black and white because a monochrome camera sensor has higher light sensitivity, which suits low-light underwater conditions with hight turbidity. Both images courtesy of Skarv Technologies.
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.
Left: Mariner USV and CORAX 600 at the IXES exercise. Image credit: UAS Norway. Right: CORAX 600 on the deck of the Mariner USV at IXES. Image credit: Skarv Technologies.
Skarv Technologies
Skarv Technologies AS designs and builds autonomous underwater vehicles in Trondheim, Norway. Its CORAX 600 AUV system comes in several models and sensor integrations, all based on a hovering, six-thruster design rated to 600 metres and made for close-range subsea work. Skarv also handles the data analysis for detection, classification and photogrammetry, as part of an end-to-end system that runs from vehicle to finished results. Skarv’s customers work in defence and commercial maritime applications, and use CORAX for mine countermeasures, rapid environmental assessment and inspection of critical subsea infrastructure.
For more information, visit www.skarvtech.com
Maritime Robotics
Since 2005, Maritime Robotics has been at the forefront of maritime autonomy, pioneering the development of advanced sea drones and autonomous maritime systems. At the core of its offering is a market-leading autonomous navigation platform enabling robust and reliable sea drone operations across mission-critical applications, serving dual-use customers globally.
For more information, visit www.maritimerobotics.com