But final decision needs to be pragmatic, most of all.

The fate of the wreckage of the Rena should be a straightforward enough matter. But the final chapter in the saga of the fully-laden container ship that hit the Astrolabe Reef off Tauranga in 2011 is proving anything but. Most recently, it has involved a claim by local iwi groups that they were not consulted about the future of the wreck in contravention of the Treaty of Waitangi. Their case was heard last week. But whatever the Waitangi Tribunal finds should not, ultimately, affect the most appropriate means of handling the wreck.

The iwi contend that a confidential agreement was formed by the Crown and the Rena's owners and insurers in October 2012. "Under the Treaty, the Crown must always practise good-faith consultation with Maori - there's been no consultation with us," said Ngai te Hapu spokesman Buddy Mikaere. The tribunal was also asked to look at why a Maritime New Zealand removal notice issued to the owners and insurers the previous year had not been enforced. A win for the iwi groups would boost their fight against a resources consent application by the owners and insurers to leave the shipwreck where it is.

That, however, seems unlikely. A Crown lawyer told the tribunal that the agreement between the Crown and the ship's owners and insurers was signed because it was feared the latter would walk away from the negotiating table. As such, it served the interests of all New Zealanders, superceding the removal notice in the process. Further, the agreement in no way bound the Crown to support the owners and insurers' application for resource consent, which was filed last month. Consultation with iwi can take place, as is customarily so in resource management matters, during the consent process when the Crown will finally make its position clear.

Whether there has been a breach of the Treaty or not, the iwi groups' pursuit of the total removal of the wreck from the reef no longer makes a great deal of sense. The only real justification is that it would prevent the continued release of oil and debris. But that is a minor problem, and one that could be largely solved by further tidying-up work. More compelling is the view that removal of all the wreck would be extremely challenging technically and highly hazardous for the salvors. The necessity for barge-mounted cranes and other equipment could also further damage the reef and its marine habitat, an outcome that surely the iwi are keen to avoid.


Nor, however, should the Rena's owners and insurers be allowed to leave the entire wreck as it is now. That may be an ideal outcome for them, allowing them to exit the scene as quickly as possible. But the best outcome for the country, the reef and the surrounding environment would be for any remaining cargo with potentially harmful effects to be removed or secured, and the site made safe for diving. Some recreational good would then come from the grounding.

There would also be an economic benefit. If the ship's owners and insurer gets resource consent to leave the submerged section of the wreck on the reef, they will pay a $10.4 million bonus to the Crown in addition to the $27.6 million being recovered for the salvage and clean-up undertaken by the country. This reflects their reduced salvage costs.

The Crown's final word should be delivered after due heed is paid to the need for consultation with the iwi and the latest information on the state of the wreck is assessed.

What the iwi groups want and what that information confirms will probably not tally. The Government must take the most pragmatic course.