Irish media has reported that a Russian submarine, positioned directly outside the entrance to Cork Harbour, was “chased off” by a British helicopter and warship because Ireland doesn’t have the ability to do so itself.

Writing in the Irish Examiner, Sean O’Riordan reported that the submarine was “just outside the 12-mile limit, so it didn’t break any international laws, but military sources have indicated that such events around the Irish coast are becoming more common”.

Details of the Russian underwater operation and subsequent British intervention, which took place six months ago, have just emerged.

Sources are cited in the article as saying that as darkness approached, a British helicopter deployed sonar equipment into the water near an unidentified submarine. This action was followed by the arrival of a Royal Navy anti-submarine frigate to monitor the submarine, compensating for the Irish naval ships’ lack of underwater surveillance technology.

“Almost all of the Irish navy’s ships had sonar between the 1960s and 1980s and the former flagship vessel, LÉ Eithne, had it until the 1990s when it became defunct and deemed too expensive at the time by the Department of Defence to replace.”

The report also notes that Russian military activities have tested British air defences near Irish shores.

Russia’s use of older Soviet-era Tu-95 ‘Bear Bombers’ has been largely unmonitored by Ireland due to the Air Corps’ lack of high-speed jets or aircraft with sufficient altitude capability. Ireland’s last fighter jets, the Vampire jets, were in service until the 1950s.