A consortium headed by ACUA Ocean, together with Houlder, Ad Hoc Marine Designs, Trident Marine, and the University of Southampton, has secured backing from the UK government to develop a new class of medium-sized uncrewed offshore support vessel.
The Project MROS consortium was awarded funding in May 2025, as part of the UK Department for Transport’s CMDC programme. Since award the MROS partners have been advancing designs for the 145ft (43m) vessel which is now progressing with resistance and seakeeping tank testing led by Southampton University Marine & Maritime Institute and the world-renowned Wolfson Unit.
Powered by a hybrid-electric propulsion system, the Uncrewed Offshore Support Vessel has been designed to operate both autonomously or optionally crewed. The prototype designs explore methanol fuel and consider efficiency, performance, maintainability and emissions reductions compared to hydrogen, ammonia and diesel variants.
Following the unmatched seagoing success of ACUA’s 46ft (14m) Pioneer-class USV design, the new vessels will also feature a Small Waterplane Area Twin Hull (SWATH), optimised for low motions and platform stability in high sea states. MROS comes just four months after USV Pioneer became the first, and so far only USV to achieve UK Maritime Coastguard Agency Workboat Code 3 regulatory approval. USV Pioneer design and trials has provided a uniquely valuable systems-design testbed, with its real-world operational insights scalable to the larger MROS platform, ensuring that the vessel’s architecture benefits from proven, full-scale learning.
Controlled in either autonomous or remote modes, or by an optionally-embarked small crew housed in a modular accommodation pod. The new vessel will be capable of operations in Sea State 6+, featuring DP1 station keeping, a 2500 nm range, 20+ days endurance, and a sprint speed of over 20 kts.
The MROS USVs are designed to satisfy a wide variety of tasks that require persistence and robustness, such as offshore logistics, maritime surveillance, subsea inspection and intervention, and the commissioning and decommissioning of offshore infrastructure. It offers a payload of 80 tonnes, to permit the embarkation of cargo or specialist sensors and payloads. The vessel features a moonpool configured with room for twin launch and recovery systems for a variety of underwater payloads, such as tethered or untethered ROVs and XUUVs.
As with USV Pioneer, the MROS USV cargo and payload bays are configured to accommodate ISO-standard transport container (TEU and FEU) sized footprints, simplifying the mechanical installation, interchangeability and logistical management of the vessel’s various tasks and maintenance.
ACUA will announce strategic partnerships with several world-leading systems developers in the coming months, as part of its strategy to develop a panoply of compatible and integrated mission payloads for both Pioneer and MROS USVs that satisfy the existing operational needs of end users, and also present new, previously unconsidered concepts.
Neil Tinmouth, CEO of ACUA Ocean, said: “The MROS project builds on ACUA Ocean’s proven ability to deploy proven and certified vessels. Most excitingly, this new design offers significant capability and cost-saving benefits over other USVs currently in development; delivering new solutions for a range of offshore commercial partners.”
John Kecsmar, Director of Ad Hoc Marine Designs, said: “We are pleased to continue our collaboration with ACUA Ocean in pushing the boundaries of what is possible. Having designed their first USV Pioneer, which has proven to be a huge success, we firmly believe in this larger platform going beyond the norm and setting new standards of offshore operability.”
Rupert Hare, CEO of Houlder Ltd, said: “We are happy to continue to work with ACUA on the exciting Project MROS following our work on Pioneer earlier in the year. This is about turning credible autonomy into offshore capability and beyond, and towards this Houlder will lead the development of a concept for launch and recovery (LARS) systems for a variety of underwater payloads, such as ROVs and XUUVs. We will also contribute to hull design and optimisation and the integration of the alternative fuel systems.”
Lee Sidaway, Director of Trident Marine Electrical, said: “We’re proud to continue our longstanding collaboration with ACUA Ocean, this time with the electrical design of their groundbreaking 43-meter partially crewed vessel, building on the success of our partnership on Pioneer. This next phase reflects our shared commitment to innovation, reliability, and pushing the boundaries of marine technology. Together, we’re shaping the future of autonomous and hybrid marine systems.”
Professor Stephen Turnock, University of Southampton, said: “The future of many maritime operations will require the use of minimally crewed clean fuelled ships at this scale. We are delighted to be part of ACUA Ocean’s journey developing such a ship bringing the
capabilities of the Southampton Marine and Maritime Institute in understanding future fuels,
autonomous systems and naval architecture.”
