An Irish lawmaker has called for an end to British military submarine activity in the Irish Sea to avoid similar incidents in the future.
The safety investigation of the encounter prompted Sinn Fein's MP Chris Hazzard to demand a halt for the British submarine operation in the Irish Sea, which "raised serious questions" and put the "lives of those on board the ferry" at risk.
"The confirmation by the British Ministry of Defence that a Royal Navy submarine was involved in a near-miss with a ferry in the Irish Sea has raised serious questions. The lives of those on board the ferry were put at risk. The British government and the British Ministry of Defence should end its submarine activity in the Irish Sea to avoid similar incidents in the future," he said.
The Marine Accident Investigation Branch (MAIB) are examining the case with the cooperation of the Royal Navy.
Stena Superfast VII ferry operated between Northern Ireland and Scotland and has the capacity for 1,300 passengers.
The Royal Navy operates seven fleet submarines and four ballistic missile submarines of the Vanguard class.
The Vanguard-class fleet entered service in the early 1990s and was set to serve for 25 years. Its replacement, the Dreadnought class of ballistic submarines for the Royal Navy is now being built and is not expected in service until the 2030s.