The Transport Accident Investigation Commission has released its final report on the Aratere ferry grounding, making no formal recommendations after finding Interislander had addressed the safety issues identified.
The Aratere ran aground shortly after departing Picton on 21 June 2024 with 47 passengers and crew aboard. None were injured and the ship was refloated just under 24 hours later.
The commission found crew members had not been trained in a steering system upgrade prior to the grounding. The ferry made a turn inadvertently towards the shoreline when it was in autopilot, and the bridge team was unable to transfer control of the rudders back to manual steering.
TAIC chief investigator of accidents Louise Cook described the lack of training as a significant oversight. "It was a large enough oversight that we opened on it and spent two years investigating it to identify this," she said.
Interislander had treated the replacement steering system as a like-for-like change without identifying operational differences before returning the ship to service. "They focused on installing the equipment, but not enough on understanding how the changes affected operation of the vessel and what crews needed to know to use it safely," Cook said.
The commission also found that safety audit and assurance checks were not being properly carried out, resulting in inadequate visibility for shoreside management on the Aratere.
Interislander has since revised bridge resource management training, updated navigation assessments, improved change management processes, and developed ship-specific steering system guidance and training. The commission believes these actions addressed the safety issues identified in the report.
"Any organisation introducing new safety-critical equipment needs to ask not just whether the system works, but how it changes the way people operate," Cook said. "The human and operational side of change management is critical to safety."