Salvage personnel are airlifted off the grounded container ship 'Rena' in the Bay of Plenty near Tauranga on October 11. The salvage crew made a daring landing on the crippled container ship leaking oil off New Zealand, as the vessel's owners apologised for the country's worst sea pollution crisis.

A salvage crew on Thursday made a daring landing on a crippled container ship leaking oil off New Zealand, as the vessel's owners apologised for the country's worst sea pollution crisis.

A helicopter winched the salvage workers onto the deck of the stricken Rena, which was "creaking and groaning" as it threatened to break apart in the North Island's Bay of Plenty after hitting a reef last week, officials said.

"It's a highly risky operation to do," Maritime New Zealand (MNZ) salvage manager Bruce Anderson said, adding that helicopters and navy ships were ready to evacuate the men at a moment's notice if the ship began to sink.

The boarding was a desperate attempt to restart efforts to offload oil from the vessel, which was abandoned on Tuesday as a storm bore down. The ship has since developed cracks in its hull and is listing badly on the reef.

Authorities, fearing that a breakup of the Rena is now inevitable, hope to drain its tanks to prevent further fuel from spewing into the environmentally sensitive area before the ship shears in two.

MNZ said anywhere from 350 to 700 tonnes of heavy fuel had already leaked from the Rena, fouling beaches and killing wildlife. They want to prevent all 1,700 tonnes on the vessel from being released if the ship breaks up and sinks.

Anderson said easing weather conditions off the coast of Tauranga were providing "a window" to get the oil off but it was still too early to say when pumping could resume.

The three-man salvage crew's operation came as the Rena's owner, Costamare Shipping Company of Greece, said it was "deeply sorry" for the disaster.

In a video statement from Greece, Costamare managing director Diamantis Manos said the company was working with New Zealand authorities to establish how the ship ran aground on October 5.

He added that it would not be appropriate to speculate on how the accident happened but described the ship's captain, who has been charged by New Zealand authorities, as "an experienced master" who "has an exemplary record".

"However, to the people of Tauranga, we want to say we are deeply sorry for the situation that has arisen and the threat you are now facing from fuel oil from the vessel washing up on the beaches of your beautiful part of the world," Manos said.

For the first time, MNZ ordered the public off oil-blackened beaches on the worst-affected 35 kilometre (22 mile) stretch of coast, clearing the way for a "massive" cleanup operation involving 500 people.

"It's hard, dirty work, but with all the agencies involved and the community pulling together, we will get this oil cleaned up," MNZ site commander Nick Quinn said as the oil continued to come ashore in sluggish black waves.

Previously, the agency had only advised people not to go onto beaches in the area, one of New Zealand's most popular tourist destinations.

Residents living near affected beaches were advised to keep their windows closed as the toxic diesel oil released fumes that leave eyes stinging and throats raw.

MNZ said 200 dead birds had been recovered and it expected the toll on wildlife to increase substantially. It said that teams were trying to round up seals in the area and had caught four so far.

It said initial fears that one of 88 containers that have toppled from the ship's deck contained ferrosilicon, which is dangerous when mixed with water, were unfounded, and the container contained a water-soluble chemical.

The Rena's second officer, who was on navigation watch when the ship ploughed into the reef, was bailed in Tauranga court, charged with operating a vessel in a manner causing unnecessary danger or risk.

The ship's Filipino captain has already been bailed on the same charge, which carries a maximum penalty of NZ$10,000 ($7,800) or one year in jail.

Explore further New Zealand braces for oil slick ship to break up

(c) 2011 AFP