An official report into the Rena as found routine violations of procedures and insufficient oversight of safety on the ship before it grounded.
The Transport Accident Investigation Commission (TAIC) has just published its final report into the incident, in which the vessel which hit the Astrolabe Reef off the coast of Tauranga in 2011. It spilt hundreds of tonnes of oil into the sea, causing one of New Zealand's worst maritime and environmental disasters.
The report said Rena manager Ciel Shipmanagement's "oversight of the Rena's safety management system was not sufficient".
TAIC discovered that three months before the grounding, the Rena was pulled up at ports overseas and found to have a high number of deficiencies.
"The number of port control deficiencies identified against the Rena and its detention in Fremantle (Australia) for non-compliance with statutory requirements indicate that the safety management system as applied on board the Rena was not meeting the objectives of the International Safety Management Code," it said.
TAIC also found the master and crew of the Rena were not following navigation and watchkeeping procedures set down in the ship's safety management system on board the ship for at least six coastal voyages leading up to the grounding.
"There were routine violations of some company procedures for voyage planning and navigation," it said.
TAIC investigator in charge Robert Thompson said the repetitive nature of the violations "from one voyage to the next indicate that failures were not one-off failures".
The indications were Ciel Shipmanagement was not "making sure the Rena was maintained".
TAIC also found fatigue was likely to have affected the performance of the Master and one of the crew during the trip to Tauranga but said there was insufficient evidence to determine if it clouded their actions immediately before the grounding.
TAIC recommended Ciel Shipmanagement improve the effectiveness of its ship safety system.
Ciel Shipmanagement disputes TAIC's claims about its safety procedures but said it had completed a safety review.
TAIC also recommend Maritime New Zealand look into using visual aids, such as a beacon on the reef, and begin to collate data on shipping movements to see if there was a need to introduce ship routing.
TAIC chief investigator Tim Burfoot told Checkpoint a key recommendation of the report was that there needed to be change to training at a global level.
Listen to Tim Burfoot
"Our recommendation is aimed at actually tackling it at the core of the problem, which is the global standard of seafarer training, and making sure that that is up to speed," he said.
The crew was not following the company's procedures or best practice safety protocols, Mr Burfoot said.
Maritime New Zealand said the beacons and shipping lanes would be considered in a Coastal Navigation Review it had under way.