Anti-whaling boat sinks after Southern Ocean collision

The high-tech trimaran Ady Gil was being towed to a research station in the Antarctic by members of the environmentalist group Sea Shepherd when the tow-line snapped, activists said.

"At this point unfortunately the Ady Gil is on the bottom of the Southern Ocean," said Peter Hammarstedt, first officer of the Ady Gil's fellow protest boat Bob Barker.

Paul Watson, the Sea Shepherd founder, said that members of the group, who see themselves as "green pirates", had tried all day to salvage the boat, but had only managed to remove oil and fuel to avoid any pollution in the sea.

"I think they were towing for about six or seven hours," Captain Watson told ABC radio. "Even the act of towing was taking more water on. The Japanese vessel had cut the vessel completely in half and made it unseaworthy."

The high-speed, $1.5 million Ady Gil had its bow sheared off when the Japanese security boat Shonan Maru 2 collided with it in the Southern Ocean on Wednesday. Video footage of the incident appears to show the environmentalists' boat lying stationary, as the Japanese ship changes course to strike it head on.