Transport Minister Steven Joyce answered these questions put to him by the Herald:
Why weren't rapid-response inflatable oil-recovery barges used?
Maritime NZ owns two and the Auckland company that makes them offered more on the day of the grounding.
"They were unsuitable. Particularly with the sea conditions, the solution was to bring the Awanuia barge in.
"The vessel to carry the oil away from the ship was not the limiting factor in getting started. The limiting factor was the condition of the pipe work and the organisation of things on the ship so that the salvors could start pumping oil.
"As it eventuated, they were able to use some of the pipework running between tanks, but in the early stages they were assessing what could be used and what was too damaged.
"If pumping began through faulty pipework, spillage into the sea from that would be difficult to stop.
"The Awanuia arrived before the salvage team was ready to use it but it was disappointing that it was damaged after only 10 tonnes of oil had been pumped on to it.
"That was an indication of how quickly the seas were cutting up. The barge arrived on the Sunday and was damaged the next day."
Were liability issues a factor in starting to pump oil from the ship?
"I don't believe so although there are movements in liability depending on who is doing what in the salvage operation.
"I was getting concerned on Thursday morning [the day after grounding] about the owner needing to appoint a salvage company, and they did soon after. I'm not sure what liability we might have assumed at that point ... but that wasn't discussed and we wanted to make sure the thing was moved forward at speed. They [the salvors on the ship] got on with the job."
Englishman Jonathan Walker was flown from Singapore to be lead adviser to Maritime New Zealand while the company-appointed experts, Svitzer, came from the Netherlands. Why wasn't there an expert on hand in New Zealand?
"That's a contradiction in terms. If you are an expert in salvaging large ships you wouldn't get the experience in New Zealand. There are only about 50 guys in the world, including masters and workers, who do this stuff. Local guys' experience is in small-vessel salvage, so you don't have a choice but to get in expertise from overseas.
"Jonathan Walker has said the reaction to this incident is as fast as any he has seen in the world and Toby Stone, who is over here from the Australian Maritime Safety Authority, has confirmed the same thing to me."
Does New Zealand have a helicopter capable of lifting containers off the Rena?
"I haven't asked because it wasn't a limiting factor as the first job of the salvage was to remove the oil. The ship [the Pencaldo, a vessel with a crane, coming from Australia] to remove containers has arrived but that can't be done until all the oil is off and by then it may all be a bit moot."
Would it be false economy to have a vessel like that available in New Zealand?
"We will go back and review all of those things afterwards but the point again is that is not a limiting factor. Those things would always have come after the bunkering of the oil and unfortunately the weather moved too quickly but the real problem was the thing getting on the reef in the first place."
"Why was it so far off course? She should never have been where she was, so there had obviously been a turn taken a bit earlier which ran it straight over the Astrolabe Reef."