Gale-force winds, high swells and rain were expected to hit the area tomorrow, giving salvagers of the cargo ship a window of only 18 hours to make the most of calm conditions, said WeatherWatch.co.nz analyst Richard Green.
Strong northeast winds of 40-50 knots were expected, bringing heavy rain and high sea swells until Wednesday.
"The system will be barrelling down on Northern New Zealand, and the Bay of Plenty looks the most vulnerable. The wind and swells are more of a concern for the salvage _ they do look significant,'' he said.
It is another setback for the team of people working to salvage the 236 metre ship that hit Astrolabe Reef on October 5 and has since spilled an estimated 20 tonnes of oil causing mounting concerns of a major environmental disaster.
Prime Minister John Key flew over the ship and was briefed at the incident control centre today before telling media he was satisfied the salvage operation was proceeding as quickly as possible.
Mr Key said a world class team was being put together rapidly.
"This is a very complex situation and we need the best experts so rash judgments aren't made. This is not a daily occurrence, it happens once every 10 years.
"I did ask whether there were other examples (of the grounding) around the world, and there were very few of them in the way this has occurred,'' Mr Key said.
The ship hit the reef in calm waters at night for "no particular reason'' and serious questions also needed to be asked, he said.
Mr Key said the salvage team would start taking oil off the Rena this evening _ a process that would take between 30 and 40 hours.
The vessel's fuel oil will be transferred from her tanks into the Awanuia fuel tanker, which arrived from Auckland this morning to help offload the 2000 tonnes of oil threatening to spill into the water.
Medical officer of health Jim Miller today released a precautionary health warning against collecting and eating seafood from water contaminated by oil, in particular from Motiti Island, and from eating seafood with an `off' or petrol smell.
A team of 10 Australian personnel arrived yesterday to join the operation.
"The removal of fuel from the ship remains the top priority. Pollutants on board the vessel including paint, grease, hydraulic oils and lubricants are being hand-carried off the vessel onto a small support vessel,'' said national on scene commander Rob Service.
Minimising any impact to New Zealand's coastline was the "absolute priority'' for Costamare Inc, said a statement from Costamare Inc _ the parent company of Rena's owners Diana Shipping Co.
Two ocean-going barges, Northern Quest and Phoenix, left port this morning carrying specialist equipment and trained oil spill responders, tasked with recovering quantities of heavy fuel oil in the water.
Further oil spill equipment is also being loaded onto two naval vessels to trial how it could be used in the response. HMNZS Endeavour is scheduled to arrive in Tauranga around 6pm.
The Green party called for oil booms to be placed across around the coastline as part of the process to"lessen the risk of large amounts of oil coming onshore.
Meanwhile, on-shore assessments are being made of all the areas which could be affected by oil blown on-shore.
The New Zealand Defence Force has personnel on standby to move to Tauranga at short notice to help with a cleanup if that should be required.
Maritime New Zealand said in a statement no further oil had been reported as seeping from the vessel overnight Saturday and fresh oil identified on Saturday afternoon had since dispersed.
Wildlife rescue teams were scouring the coast for affected wildlife.
Another oiled little blue penguin has been recovered and taken to the wildlife facility in Te Maunga, bringing the total number of oiled birds recovered to eight. All are in good condition and were being washed and cared for, Maritime NZ said.
