"They're doing their first dive of the vessel.''
On this inspection dive, experts would assess the damage and come up with a plan to salvage the vessel, Mr Saunders said.
"The way that these things work is the owner appoints a salvage company and when they do that the salvage company will be able to plan their own assessment to salvage the vessel.
"So they come up with the action plan and at this stage no decisions about that have been made.''
Mr Saunders said the vessel could be saved but a lot of work needed to be done.
"Before anything happens two things need to be taken into account, first is the safety of the people and the environment ... and second is a good plan to get it off the reef,'' he said.
"They won't pull it off the reef unless the hull is in a good condition ... and can float safely somewhere where it can be fixed.
"Then they have to get it off the reef and to do that they need to make the ship as light as possible and get good horsepower to get it off, using a large tug or several tugs because you're going to need a bit of power to get it off. Then of course the tide has to be high at the time when you pull it off.
"Then once it's off it will need to be towed somewhere for repair, whether that be in New Zealand or overseas.''
One way to get the ship lighter was to remove the oil from the ship, which Mr Saunders said could be a challenge.
"When you pump oil into a tanker off another vessel it's another major exercise and is quite difficult because you have to pump heavy fuel into a tank at sea. It makes it easier if the sea is dead calm, like it is at the moment.''
As well as to make the ship lighter, experts would remove the oil for environmental reasons.
"They wouldn't risk leakage if the hull isn't fully intact, and this is normal practice if salvaging a ship off a reef,'' Mr Saunders said.
It was common practice to use air bags to lift ships from below the sea surface but Mr Saunders said this technique was highly unlikely to be used, as the ship was not sitting low in the water.
"When ships are sunk in the water you can lift them up with lift bags that are pumped with air to give buoyancy but since this ship is not sitting low in the water, you won't be able to do much with the air bags,'' he said. ``It is normal consideration with salvages but in this case the vessel will not have much water inside so will not be a lot of use.''
He said it would cost "a fair bit'' and take a little while before the ship was saved, but said money was not at the forefront of the operation.
"At the end of the day the safety of the people and the marine environment is at the top of the list, not money concerns.''
Mr Saunders said it was highly unlikely experts would sink the vessel.
This decision would be made at regional council level, with input from the regional harbour master, Carl Magazinovic.
Wildlife affected by spill
Maritime New Zealand have confirmed oiled birds on the water have been found as a result of the oil spill surrounding the grounded cargo ship off Tauranga.
Fears are growing the stranded ship, which is haemorrhaging oil into the sea, has the potential to cause a major environmental disaster.
The 236m cargo vessel struck Astrolabe Reef near Tauranga Harbour early on Wednesday, causing a 5km oil slick that has already killed some wildlife.
But a make-shift care centre to look after wildlife caught in the oil slick is now ready for business.
The National Oiled Wildlife Response Team set up the Wildlife Health Centre camp at the Te Maunga Wastewater Treatment Plant yesterday.
Four birds have already been found dead in the slick caused by the cargo ship Rena, aground at Astrolabe reef.
Any other birds coated in oil will be taken to the site to be cleaned and cared for.
The centre consists of two shipping containers that have water heaters operated by gas, four wash basins, a ventilation system to suck out toxic fumes as birds are washed, a drainage system, a holding tank for waste water, warming facilities and swimming ponds.
The team's technical adviser, Bill Dwyer, brought the centre up from Palmerston North.
"Within 30 minutes of dropping this off the truck we can have it set up and ready to go,'' he said.
Mr Dwyer said the centre was created in 2002.
He was called to help in the Jody F Millenium grounding but the wildlife rescue facilities were limited, he said.
"The rescue equipment wasn't as suitable as it could have been. This can be used in all sorts of configurations. It can be ramped up if the spill gets worse,'' Mr Dwyer said. Birds taken to the base will be washed with special detergent, which usually takes two people a bird to do, before birds are warmed, fed and given a swimming pond to recuperate in as their natural protective oils return to their feathers.
Local wildlife expert Bob Mankelow said volunteers from Tauranga and elsewhere in New Zealand were coming to help.
"It takes about 20 minutes a bird.''
The team did not know how many birds they were expected to deal with but they were well set up for it, Mr Mankelow said.
Specialist equipment needed
Oil spill response teams and wildlife workers were today travelling to the area and experts are now looking to use specialist equipment to scoop the oil out of the water.
Maritime New Zealand said while oiled birds have been found on the water, there have not been any confirmed reports of oiled seals. Anyone who finds any affected wildlife are advised not to handle the animals themselves, rather they should call 0800 333 771.
The wildlife team will need precise details of the location, animal species and numbers of any oiled animals encountered. Oiled animals will be transported by the wildlife team.
Maritime New Zealand national on scene commander Rob Service said a flight over the ship this morning found a sheen of oil is still spreading from the ship but there is no evidence of further spillage of heavy fuel oil.
Observers on the flight said there was no sign that oil is moving towards Mayor Island at this stage.
"With regard to the location of the leak, clearly the oil is coming from the tanks ... however the tanks themselves have not been breached," Mr Service told Radio New Zealand.
"We believe the oil is coming from the pipe work which is connected to the tanks, and unfortunately the pipe work runs along the bottom of the ship, along the keel, and of course that is an area that's been subject to extensive damage."
Mr Service said a salvage team is on the ship, looking in particular at the possibility of removing the oil from the ship. This would involve bringing another vessel as close to the Rena and transferring the oil to the second vessel via pipes, he said.
Trials have resumed this morning using the dispersant Corexit 9500 after inconclusive results from yesterday's aerial operations.
Mr Service said an oil boom cannot be used at this stage due to the conditions, and dispersant was currently the best option.
He said computer modelling shows the oil is "likely to drift around the vicinity of the ship", but it is difficult to predict exactly where the oil will go.
"Our modelling doesn't show any shoreline impact for several days. And any shoreline impact is going to depend on the amount that is spilled.
"The worst case scenario is a significant shoreline impact. which is why we have teams on standby ready for shore line impact."
Mr Service said that over 90 people were already involved in the response, with more being brought in as the wildlife and shoreline teams were expanded. International expertise was also being called on.
Four teams of three people each are based at Motiti Island and another two field teams will be working on the mainland coast.
Matthew Watson, a spokesman for Svitzer Salvage, who are undertaking the salvage, told Radio New Zealand a naval architect is due to arrive from Holland this afternoon.
"A naval architect calculates different weight scenarios on vessels. His role is central to developing the overall salvage plan," Mr Watson said.
"The naval architect looks at all sorts of numbers and different calculations to get a stronger idea of what the vessel can actually tolerate, how she could best be shifted - it is a very precise science that can't be rushed."
Minister of Transport Steven Joyce is also to travel to the Bay of Plenty today to see the vessel for himself.
He said the priority was to remove the oil from the ship as quickly as possible.
"The difficulty is that the situation is deteriorating and according to the advice I've received, there's the possibility it could break up and sink - it's certainly serious what's going on there," he told the Herald last night.
"(Emergency response teams) are certainly moving as fast as they can - it's been a bit frustrating for everybody in terms of getting the right equipment to achieve the removal of the oil and containers."
Environmental threat 'worrying'
Maritime New Zealand (MNZ) pollution response service manager Andrew Berry told Radio New Zealand he was "very worried'' about the threat to the environment posed by the slick.
"It has the potential to be very, very serious indeed, simply because of the age of the ship, the damage that she's sustained and the 1700 tonnes of heavy fuel oil on board.''
The main priority of salvage crews now was to get as much of the fuel as possible off the ship, he said.
It is still not known how much oil has spilt from the vessel.
"We stand on the brink of disaster if the salvage goes wrong," said Shane Wasik, NZ Underwater Association president and a local diver.
"Although divers have joked about having a new wreck in that bay for years, the threat of an environmental disaster far outweighs any attraction of a new wreck."
The area is nationally renowned for its marine life, including whales, dolphins, seals, sharks and rarities such as turtles, sunfish and whale sharks.
A dark sheen, in parts thick and murky, was approaching Mayor Island last night as a large team of wildlife experts swung into action.
"More needs to be done"
Motiti Island resident Kereama Hoete told TV3 the vessel was right on his doorstep.
"We've seen so many ships go past ... they're either on this side of the rocks or right on the other side of the rock. This is the first one I've known to hit it. I don't know what happened with their GPS, I don't know whether they were asleep."
Mr Hoete felt not enough had been done, and hoped the vessel was moved before rough weather broke it up or spilt the containers into the sea.
Four birds were found dead yesterday, and this morning a team of experts with experience in catching and treating oiled birds will be making beach searches on Motiti Island and the Maketu Peninsula.
Mr Service said the ship was carrying hazardous substances, but there were no reports any of these had leaked.
Maritime New Zealand has ordered the vessel's owners to begin a salvage operation.
Salvage operation "slow process"
Spokeswoman Sophie Hazlehurst said planning for the salvage would be a slow and steady process.
"The salvage company is now working through a process. That's going to take some time. That's good by us - the last thing we want is for them to move too quickly and rush this."
Mr Joyce rejected Green Party claims that the spill highlighted dangers involved in deep-sea oil-drilling projects being investigated by the Government.
But Green Party spokesman Gareth Hughes said the event was a "wake-up call".
"It shows the risk. There's a significant quantity of oil and this is going to have a large impact on the local environment, especially bird life."
International salvage company Svitzer was yesterday appointed to manage the salvage operation and has staff on board the ship.
It is not known how the vessel came to hit the reef, and two separate investigations are being made.
Two Transport Accident Investigation Commission investigators are to board the Rena this morning as part of an inquiry into the grounding.
Boaties are being asked to keep well away from the vessel, which is surrounded by a 1km exclusion zone.
Maritime Union spokesman Selwyn Russell described the situation as "beyond belief".
Mr Russell said the ship's crew and those leading the response to its grounding were "under the magnifying glass" and needed to be brought to account.
"This has ramifications everywhere. If we can't deal with this, right here and now, how can we deal with oil exploration?
"She's sitting high and dry and we still don't know how it got there."
Local mariners are also perplexed by the accident.
But Mount Maunganui Environmental Group spokesman Rob Paterson said now was not the time for pointing fingers.
"Let's not agonise over how it happened and why," he said. "Let's just get it off there."
