Stena Superfast VII and Royal Navy submarine report published

Our accident investigation report into the near miss between the ferry Stena Superfast VII and a submerged Royal Navy submarine on 6 November 2018, is now published.

Statement from the Chief Inspector of Marine Accidents

On 6 November 2018, the lookout on board the ferry Stena Superfast VII spotted a submarine’s periscope close ahead. The officer of the watch then took immediate and effective action, turning the ferry to avoid a genuine risk of collision with a submerged submarine. The incident happened because the submarine’s control room team had underestimated the ferry’s speed and overestimated its range, resulting in safety-critical decisions being made based on inaccurate information.

Although there was no collision, this was the third accident or incident between a dived Royal Navy submarine and a surface vessel in 4 years, which is a matter of significant concern. The Royal Navy co-operated with the MAIB’s investigation into this near miss and has taken a series of actions, intended to prevent recurrence, in response to this, and the other similar incidents. However, I have today recommended that the Royal Navy undertakes an independent review of the actions that have been taken, in order to ensure that the risk of similar collisions has been reduced to as low as possible.