The UK's Marine Accident Investigation Branch (MAIB) has begun its investigation into an incident on November 6 last year wherein a submarine and a Ro-Pax ferry operated by Stena Line narrowly avoided colliding with each other.
Involved in the near-miss in the Irish Sea were the 203- by 25-metre Stena Superfast VII and a Royal Navy submarine, the name and type of which the Ministry of Defence (MoD) has not disclosed for reasons of operational security.
The submarine was at periscope depth while navigating the sea lane between Cairnryan and Belfast during the same time that Stena Superfast VII was in the area.
A spokesperson of Stena Line confirmed that the ferry, its passengers, or its crew were never in any danger at any time throughout the incident.
Both the Royal Navy and Stena Line have pledged their full co-operation in the MAIB's investigation.
