Update: UK's first future subsea surveillance ship arrives in Merseyside for conversion

The UK's newly acquired future Multi-Role Ocean Surveillance ship sails into Cammell Laird shipyard, Birkenhead, Liverpool, on 19 January. (Royal Navy)

The UK Ministry of Defence (MoD) has purchased a second-hand commercial offshore patrol vessel from P&O Maritime Logistics' subsidiary Topaz Energy and Marinefor conversion into a specialist ship dedicated to protecting the country's critical subsea infrastructure.

The vessel, which is currently named MV Topaz Tangaroa, arrived at Cammell Laird shipyard in Birkenhead, Merseyside, for refitting on 19 January.

Topaz Tangaroa will be converted into the first of two plannedMulti-Role Ocean Surveillance (MROS) ships for underwater surveillance and seabed warfare, to be operated by the Royal Fleet Auxiliary (RFA). According to the MoD, the vessel will be formally handed over to control of the RFA in the coming days. Following the completion of its conversion activities, the vessel is planned to join the fleet around mid-2023.

Topaz Tangaroa, which will be renamed for the RFA service, was built byNorwegian shipbuilder Vard and delivered to Topaz Energy and Marine in 2019. Since then, it has been used to support a mix of underwater operations, including work on oil rigs, construction, maintenance and inspection work, as well as autonomous submarine operations.

It has an overall length of 98.1 m, a beam of 20 m, and a deadweight displacement of 3,000 tonnes. It is equipped with a helipad, crane, and a large working deck, and features a moon pool in the underside of the hull for the through-hull launch and retrieval of submersible capabilities,