By Samantha Hayes
3 News had two experienced seamen examine pictures of today's clash supplied by both the Japanese whalers and Sea Shepherd.
The high sea drama could end up with a court battle to find out who is to blame, but it would be a long and complicated case.
Pictures supplied by the Japanese whaling fleet show the Sea Shepherd vessel Ady Gil aggressively targeting a Japanese ship with lasers and dragging a rope across their path.
The whalers say they were deliberately trying to entangle their rudder and propeller.
"It's quite simple," says Captain Jim Varney. "She's being used in a harassment situation."
Capt Varney is an experienced maritime accident investigator and has been a captain for more than 50 years. He says both vessels were ignoring international maritime law, and suspects the Ady Gil unintentionally moved into the Japanese boat's path.
"It may have been a miscalculation on the part of the Ady Gil. He may have been attempting to cross the bow."
Captain Tim Wilson from the New Zealand Maritime School agrees that the Ady Gil was accelerating when it was hit by the Japanese ship.
"We can see the two vessels coming together," he says of the footage supplied by Sea Shephard. "Clearly it appears that they are going to pass clear - at this point, we can see the Ady Gil moving very slowly across."
But watching the Japanese footage, he adds: "The Adi Gil appears to suddenly start moving - you can see the sudden increase in wake as she moves forward."
But the motivation behind the move is murky.
"They tried to accelerate and get some control and move ahead of the bow," says Capt Wilson. "The other thing could have been that they moved into the impact zone."
Both captains agree that the Japanese whalers and Sea Shepherd are at fault.
"Both vessels had an obligation to take action to avoid the collision much earlier than they appeared to," says Capt Wilson.
Maritime New Zealand says an investigation is underway, which will consider pictures from both sides to decide what legal action, if any, will be taken.
3 News