The Department of Conservation has been told it has insufficient expertise to assess the risks to passenger ships in the sub-Antarctic, after a ship it had allowed into the Snares Islands zone had its hull pierced after it hit a rock.
It will now follow a recommendation from the Transport Accident Investigation Commission that it appoint an expert to oversee navigation safety in the Southern Ocean area.
The operator of French passenger ship L'Austral has also been told it needs to improve its standard of voyage planning, and level of crew training.
The details are contained in a report release this month by the Transport Accident Investigation Commission.
L'Austral is a French-registered passenger vessel that was operating a 16-night cruise of the South Island, including its sub-Antarctic islands in January last year with 200 passengers and 156 crew.
The TAIC report said on arrival in the Snares, passengers spent the morning on shoreline excursions in small boats, but the weather turned bad and L'Austral moved into sheltered water to pick them up.
While the ship's master was focused on doing this, the vessel drifted into a zone not suited for safe navigation, and hit the rock. It pierced part of the hull which flooded with water, but the the ship was able to continue to another sub-Antarctic island before returning to New Zealand for temporary repairs. Nobody was injured.
The commission found that L'Austral inadvertently entered the 300-metre zone it was not permitted to enter, as the charts showed overfalls (turbulence caused by submarine ridges and strong currents), eddies and breakers.
The uncharted rock was in an area that the commission considered was not suitable for the safe navigation of ships the size of L'Austral.
The commission said better controls were needed, given the sensitive environment and the likelihood that shipping activity would increase in future.
Spokesman Peter Northcote said TAIC found that the Department of Conservation had given L'Austral a coastal permit to go up to 300m from the shoreline.
"But it had done that without conducting a formal risk assessment, and to do that it really needs the appropriate maritime expertise.
"So the commission has said to DOC you really need to have this expertise for considering such permits, particularly around sensitive areas such as the Snares Islands, where effectively DOC is the harbourmaster, and it has agreed to that recommendation," Mr Northcote said.
DOC's southern South Island operations director Aaron Fleming said it would be appointing a suitably qualified person to manage the safety of navigation in the remote and sensitive environment.
The Snares Islands, south-west of Stewart Island, are a UNESCO World Heritage site.
"DOC is already in the process of obtaining expert maritime advice for the purposes of implementing the recommendation," Mr Fleming said.
The commission also found the voyage planning and the standard of management on the bridge did not meet international standards, and that the operation of L'Austral's electronic chart display and information system did not meet good practice, nor the standards set out in the operator's safety management system.