美国反捕鲸组织“海洋守护协会”在去年冬天新近购入高科技“蝙蝠船”，在最近的捕鲸季节中与日本船只发生激烈冲突，试图阻止捕鲸船的恶劣行为。而近日，这艘蝙蝠船同日本捕鲸船在南极海域相撞后沉没，所幸没有造成人员伤亡。

Japanese ship sinks whale protest boat Ady Gil

The high-tech stealth boat Ady Gil was cut in half and sunk by a Japanese security vessel in Antarctic waters today, dramatically upping the stakes in the annual struggle between whalers and protesters.

Sea Shepherd group leader Paul Watson told Fairfax Media the $1.5 million Ady Gil was sinking, but its six-man crew had been rescued and was uninjured.

Earlier today, the fleet was contacted for the first time by the Ady Gil and Sea Shepherd's "secret" third vessel, the Bob Barker.

Captain Watson, aboard the Steve Irwin, said he was still 500 nautical miles from the scene.

"This seriously escalates the whole situation," Captain Watson said of the collision.

The ICR said the Ady Gil came "within collision distance" directly in front of the Nisshin Maru bow and repeatedly deployed a rope from its stern "to entangle the Japanese vessel's rudder and propeller".

The statement accused the activists of shining a laser device at the Nisshin Maru crew and launching acid-filled projectiles, one of which landed on the vessel's deck.

After broadcasting a warning message, the Nisshin Maru sprayed the Ady Gil with water cannons to prevent it from coming closer, the ICR said.

Captain Watson told Fairfax in November the Ady Gil would be used to intercept the whaling fleet's chaser boats.

"What I think we can do is latch onto at least one of the three harpoon vessels and keep them out of the picture," he said.

Looking more like Batman's spacecraft than a boat, the biodiesel-powered trimaran Ady Gil arrived at the Southern Ocean stand-off between Japanese whalers and activists yesterday.

It was reported this morning to be about 50 nautical miles away from the whaling fleet.

Japan's Fisheries Minister Hirotaka Akamatsu had earlier warned two security ships would be used to protect the whaling fleet, intervening when Sea Shepherd tried to block the transfer of harpooned whales to the factory ship Nisshin Maru.

Captain Watson this morning announced the existence of a secret third ship in the Sea Shepherd flotilla.

He said he was confident that with three ships, Sea Shepherd would be able to cause maximum disruption to the whaling, which has been underway for around a month.

Japanese whalers have stepped up security this year, sending spy flights from Australian airports to track protest ships.

The Hobart flights were paid for by Wellington-based Omeka Communications, air industry sources told Fairfax.

Omeka is a public relations firm retained by Japan's Institute of Cetacean Research. The Hobart flights carried Omeka's principal, Glenn Inwood, who is an institute spokesman, and another man, the sources said.

The operation started in December when the Steve Irwin left Fremantle to intercept the whaling fleet, which this year is targeting 935 minke whales and 50 fin whales.

WA pilots said surveillance flights continued out of Albany for some days, costing a ''truckload'' of money. Two men aboard the flights told locals they were ''looking for people who were looking for whales''.

The Rudd Government has repeatedly called for caution by both sides in the wilds of the Antarctic.

"We have reminded the masters of protest vessels of their obligations under international law to take all steps to ensure safety of life at sea, particularly in the inhospitable conditions of the Southern Ocean," Environment Minister Peter Garrett said recently.

"We are also passing the same message to the government of Japan."