The 24m-long, lightweight boat lost its bow section in the collision off Commonwealth Bay. It was hit by the Shonan Maru 2, a harpoon vessel.
The Ady Gil was left to sink after its crew of six were taken off safely by another Sea Shepherd vessel.
The vessel, Bob Barker, is a former Norwegian whaler only recently made available to Sea Shepherd through a $5 million private donation.
It was close by and was able to video the incident (see link below).
The footage shows the Ady Gil stopped, ahead but to one side of the approaching ship, which is firing water cannon at the trimaran.
The Japanese vessel veers hard to starboard toward the Ady Gil, before straightening and starting a turn back to port just as the trimaran engages drive in a vain attempt to clear the ship’s bows.
In the heavy impact which follows, only marginally ahead of its wheelhouse, the Ady Gil is almost pushed under before bobbing back up minus its bow.
It is clear that the crew were lucky not to suffer fatalities or injuries. Four people were on the open bridge at the aft end of the wheelhouse. They dived to the deck as the Ady Gil was hit.
Japan’s Institute of Cetacean Research (ICR) has said that, before the collision, the Ady Gil had been approaching to within “collision distance” ahead of the Japanese ship and “towing a rope from its stern with the intent to entangle the Japanese vessel’s rudder and propeller”.
Sea Shepherd crew were also accused of firing potentially harmful green laser rays and balls of butyric acid from a launcher.
For Sea Shepherd, the ramming could not be justified and was intended. Its Australian director, Jeff Hansen, told press that the Japanese ship had had the Ady Gil “in its direct line of sight, coming straight for it”.
Captain Paul Watson, aboard the organisation’s flagship Steve Irwin which was 500 miles away, said: "This seriously escalates the whole situation."
The 50-knot, wave-piercing Ady Gil was the former Earthrace, which set a 61-day circumnavigation record in 2008.
The fibreglass-and-carbon trimaran was taken on by Sea Shepherd last year and named after the American who donoted $1 million for its purchase.
Seemingly an odd choice for such work, the Ady Gil would, Sea Shepherd thought, be able to use its speed and manoeuvrability to block harpooners’ lines of sight and cause other disruption to whaling fleet movements.
Ady Gil is co-owner of American Hi Definition Inc, which makes film production equipment, from trucks to studio consoles and cameras.
Bob Barker, the latest Sea Shepherd vessel donor, is a retired US TV game shows host, best known for CBS' The Price is Right.
Related links
Collision video
Sea Shepherd
Norway targets whales as Shepherd targets whalers