In its 2017 Safety Digest report, the UK MAIB published its findings into the sinking of an unmanned survey vessel due to a defective butterfly valve that was not fully closed, providing a description of what happened and the lessons learnt in an attempt to prevent similar accidents from occurring. Mistakes like this should have been picked up in safety inspection leading to concerns over poor inspection regime.
The incident
A fisheries survey vessel sank while alongside a marina berth. The vessel, a 17m long aluminium catamaran, had two independent engine rooms, each located in the port and starboard side hulls. The vessel was unmanned at the time of the accident.