No date for second seabed warfare ship

The Ministry of Defence has declined to give a date for the introduction of additional specialist shipping for underwater infrastructure protection, pointing instead to upgrades for RFA Proteus and to commercially provided solutions, in response to parliamentary questions.

Ben Obese-Jecty, Conservative MP for Huntingdon, tabled two questions on paragraph 49 of the Defence Investment Plan, published on 30 June 2026, asking what novel funding mechanisms would be used to increase the resilience and protection of critical underwater infrastructure, and by what date additional specialist shipping would be introduced. Minister of State Luke Pollard returned an identical answer to both.

“As set out in the Defence Investment Plan, the Ministry of Defence will invest £330 million over the next four years in critical underwater infrastructure protection, including enhanced capabilities for RFA PROTEUS,” Pollard said. On the funding approach, he added: “We will also explore opportunities to partner with industry and investors on commercially provided solutions to increase the resilience and protection of associated capabilities.”

Asked when additional shipping would arrive, the minister gave no date, stating: “The timelines associated with programme delivery remain will be determined as specific capability solutions are down selected.” The answer makes no reference to a second purpose-built vessel.

Proteus was always described as the first of two Multi-Role Ocean Surveillance Ships. The programme was announced in October 2022 by then Defence Secretary Ben Wallace in the aftermath of the Nord Stream pipeline sabotage, with the first ship to be bought as a ready-built commercial vessel and converted, and the second potentially built in the UK. Proteus began life as the offshore support vessel MV Topaz Tangaroa, purchased by the MOD for £70 million in early 2023 and converted at Cammell Laird in Birkenhead, a programme accelerated using funds freed by the cancellation of the National Flagship. She entered service in October 2023.

The second hull has not progressed at the same pace, though, as a ministerial letter dated 28 January 2025 reaffirmed that Proteus was the first of two such ships and stated that the second remained in its concept phase, with the Strategic Defence Review to consider how best to augment the existing vessel. It appears that funding originally associated with the second ship has been directed toward extending the service life of the survey vessel HMS Scott, keeping her in use into the early 2030s.

As previously reported by the UK Defence Journal, the decision to invest in upgrading the existing vessel suggests Proteus will carry the mission alone for some time yet. The reference to commercially provided solutions leaves open the possibility that additional capacity is sought through chartered or industry-operated platforms rather than a second purpose-built naval hull, an approach that would mirror arrangements used elsewhere for survey and support tasks.

Proteus operates with a core Royal Fleet Auxiliary crew augmented by Royal Navy specialists, and is fitted with a moonpool, heavy-lift crane and remotely operated vehicles for work on the seabed. The ship has been used as a testbed for underwater systems, including trials of a containerised towed survey vehicle off Portland, as the Royal Navy develops its seabed warfare capability against a backdrop of damage to cables and pipelines in the Baltic and North Sea.