In a sadly predictable turn of events, plans by a controversial anti-whaling group to disrupt Japanese cetacean hunting with a high-tech carbon fibre boat have not gone well.

A collision between the Sea Shepherd group’s catamaran Ady Gill and the Japanese vessel Shonan Maru No. 2 has resulted in what Sea Shepherd says is “catastrophic damage” to their vessel. Its crew have been taken onboard another Sea Shepherd ship and the Japanese vessel was not damaged.

“The Ady Gil is believed to be sinking and chances of salvage are very grim,” says a statement on the anti-whaling group’s website.

The actions of the Sea Shepherd group are hugely controversial, even among those who oppose Japanese whaling. The Institute for Cetacean Research says they have been attempting to foul the propeller of one whaling ship, and they have also been shining high-powered lasers and firing “acid-containing ball-like projectiles” at the Japanese crew.

Exactly what happened in this case is unclear. The Japanese Institute for Cetacean Research says the Ady Gill collided with the Shonan Maru No. 2 and that whaling vessels have been under attack. Sea Shepherd says the Shonan Maru No. 2 “deliberately rammed” the Ady Gill in “an unprovoked attack”.

Video uploaded by the Institute for Cetacean Research appears to show both vessels moving forward on a collision course before the smash (large file, also embedded here). However the Sea Shepherd statement insists both vessels were not moving when the Japanese ship “suddenly started up and deliberately rammed the Ady Gil”.

Under the general laws designed to avoid collisions at sea the ship that has the other on the starboard (right) side when both are on a collision course would generally give way. However it could also be argued that the Japanese vessel is far less manoeuvrable than the Sea Shepherd ship, putting the onus on the latter to avoid collision.