On Monday, February 12, 2007, the Japanese whaling ship Kaiko Maru was intercepted by the Sea Shepherd ship Robert Hunter as it was chasing a pod of whales. The Robert Hunter intervened by crossing in front of the Kaiko Maru, which allowed the whales to escape.

The Kaiko Maru then came alongside the Robert Hunter and swerved into the starboard side of the Sea Shepherd ship to push it into some ice.

The Robert Hunter's hull was penetrated and a large hole ripped open into the forward compartment area above the main deck. The shoving of the Robert Hunter against the ice caused damage below the water line on the port side of the engine room compartment.

Both ships then moved into the ice and then began to work their way out of the floe when, suddenly, the Kaiko Maru backed up and rammed into the stern port side of the Robert Hunter. This collision penetrated the hull and opened a one-meter gash in the bulwarks above the main deck.

After striking the Robert Hunter twice, the Kaiko Maru then issued a Maritime Distress signal. Both the Robert Hunter and the Farley Mowat responded to the distress request but the Kaiko Maruwould not respond. New Zealand Search and Rescue informed both Sea Shepherd ships that the Kaiko Maru reported they were in "grave and imminent danger"

Captain Paul Watson assured New Zealand Search that they were not threatening the whaler, and that it was the whaling ship that had inflicted damage.

The Institute for Cetacean Research, the Japanese government agency that owns and operates the whaling ships, has accused the Robert Hunter of ramming the Kaiko Maru.
Sea Shepherd believes that the public relations firm employed by the Japanese whalers is spinning this story to make it appear that the whalers are the victims.

So who rammed whom?

The collisions were fully documented by the film crew onboard the Robert Hunter. This evidence clearly shows what occurred.

Furthermore, Sea Shepherd has no problem with admitting to ramming a whaling ship involved with illegal whaling, if we had in fact done so. We have always accepted responsibility for our actions. In this case, Sea Shepherd categorically refutes the Japanese accusations that they were rammed.

The Farley Mowat and the Robert Hunter are focusing their attentions specifically on the Nisshin Maru, the factory ship of the whaling fleet.

In the situation involving the Kaiko Maru, it was the whaling ship that was the aggressor. 
The Kaiko Maru was free to leave unhindered by Sea Shepherd.

The Sea Shepherd ships are presently in pursuit of the Nisshin Maru.