Watson, who expects to encounter the Japanese fleet in the Southern Ocean within days, said the 54-metre (177-foot) Farley Mowat had been fitted with a ram which could slice into the hull of a whaler.

Asked whether he would be prepared to use it, Watson, 56, replied: "Yeah, above the waterline, you know, enough damage to force them back to port.

"Last year I sideswiped the Oriental Bluebird supply vessel and drove them out of the area."

Watson said the Sea Shepherd Conservation Society was this year also deploying a second, faster ship, the Robert Hunter, a helicopter and a total of 70 crew from 14 countries against the whalers.

The International Whaling Commission imposed a moratorium on commercial whaling in 1986 but Japan has continued hunting for what it calls scientific research.

Critics reject this claim, and Japan makes no secret of the fact that the meat from the hunt winds up on dinner plates.

A fleet of six Japanese ships has been deployed to the Antarctic on an expedition to kill about 850 minke whales and 10 fin whales in this year's southern hemisphere summer, the Japanese Fisheries Agency announced.

"We're not going down to protest whaling, we're going down there to obstruct and harass and do everything we can to stop them from continuing to kill whales illegally," Watson said.

The Canadian-born activist has been accused of using violent tactics in his conservation efforts, but said he had never injured anybody.

"Yeah, we sank half of Iceland's whaling fleet in 1986, sank three Norwegian whalers, we sank two Spanish whalers. We were never charged with any crimes for this -- they were all illegally operated."

He acknowledged that his ship was unregistered and thus illegal after Belize cancelled its registration last month, but said he did not care.

"When people call us pirates I don't really have a problem with that -- we're pirates of compassion in pursuit of pirates of profit."

The Japanese fleet will also be harassed by the international conservation group Greenpeace, whose fastest ship, the 72-metre Esperanza, will leave New Zealand for the Southern Ocean on January 25.

Watson, a founder member of Greenpeace, left the organisation in 1977 after disagreements over tactics and has taken a more aggressive approach with Sea Shepherd.

"Greenpeace has become a multinational corporation," he told AFP. "They do a lot of ocean posing and pretend to solve problems but the bottom line is that they're there to raise money."

Greenpeace New Zealand executive director, Bunny McDiarmid, dismissed Watson's charges as "ridiculous", adding that the organisation was firmly committed to non-violent protest.

"We're working in an area of the world that's really remote, it's very dangerous -- the Southern Ocean is a fairly formidable place to be operating in.

"Greenpeace takes as many safety precautions as we possible can to ensure the safety of both us and the Japanese whaling fleet."

Watson's plans were also condemned by the Australian government, a strong critic of Japan's whaling programme.

"It really puts the cause of whale conservation backwards," said Environment Minister Ian Campbell.

"I implore Captain Watson to comply with the law of the sea and not do anything to put at risk other vessels on the high seas and therefore human life."

Related Links
Sea Sheperd
Follow the Whaling Debate