UK, French, Norwegian MPAs combine to hunt reported Russian submarine

Torpedo first for Royal Air Force Poseidon sub-hunter
A multinational search for a Russian submarine off Ireland’s west coast has been supported by several maritime patrol aircraft (MPAs), including a UK P-8A Poseidon. The UK P-8A pictured is flying off Scotland in 2021.

Maritime patrol aircraft (MPAs) from the United Kingdom, France, and Norway have been working together to prosecute a suspected Russian submarine target, in a combined operation off the west coast of Ireland, according to media reports.

Irish and wider international media reported in early June that the three countries were working together to search for a Russian submarine off Ireland’s west coast, covering waters off Donegal and Sligo on the northwest coast and off counties Mayo and Clare further south.

Writing in The Daily Telegraph, former UK Royal Navy (RN) officer Tom Sharpe said “To seasoned aircraft spotters this can mean only one thing – there was a Russian submarine there.”

The UK and Norway deployed Boeing P-8A Poseidon MPAs to the northern search area, while France flew a Dassault Bréguet Atlantique MPA over the southern area, the media reports noted.

Sharpe added that the RN had also diverted the towed array sonar-capable Type 23 frigate HMS Richmond south from Iceland, and had deployed the Trafalgar-class nuclear-powered attack submarine (SSN) HMS Triumph from Faslane, Scotland. An ASW frigate and an SSN add more layers to the search structure.

The various media reports suggested that the possible Russian submarine presence may have related to critical underwater infrastructure (CUI) located in the region. The presence of international partners to conduct the search activity underlines the importance of partnering in protecting CUI across the Euro-Atlantic theatre. The possible submarine presence off Ireland’s west coast is something that could be both expected and anticipated, given the regularity of recent CUI incidents across the theatre, the strategic importance of CUI off Ireland, and Ireland’s own relatively limited capacity to patrol what is a large area of operations off its west coast.

Recent Euro-Atlantic CUI incidents include disruptions to data cables off Lofoten, Norway (November 2021) and Svalbard, Norway (January 2022); explosions on gas pipelines (Baltic Sea, September 2022); and damage to cables and pipelines caused by an anchor being dragged across them (Baltic, October 2023).

According to, four cables make landfall in western Ireland – one each at Killala (County Mayo) and Lecanvey (County Mayo), and two further south in Galway.

The apparent Russian interest in CUI off Ireland’s west coast is not without precedent. In May 2023, Irish media reported that Irish Naval Service and RN vessels were monitoring some Russian ships, while other Russian ships were reported to be conducting unusual manoeuvres off Galway close to a newly laid cable. In August 2021, Irish media reported that Russia’s Project 22010 survey and research vessel Yantar had been spotted sailing close to Irish west coast waters.

Ireland also does not possess maritime platforms like state-of-the-art MPAs, frigates, and SSNs that have high-end capability to conduct CUI security and related anti-submarine warfare (ASW) tasks. While this means Russia could see a seam between Irish and UK maritime security it can exploit, it also means that multinational co-operation is essential to offsetting such efforts and threats.

by Dr Lee Willett, London