"prop fouling" iswhat they were doing.
Ships Collide In Antarctic Whaling Clash - CBS News
The Institute of Cetacean Research, the non-profit organization that conducts the hunt, said the Ady Gil came "within collision distance" of the Nisshin Maru's bow and repeatedly dangled a rope in the water that could have entangled the ship's rudder and propeller.
The Ady Gil's crew lobbed small projectiles designed to release a foul smell, and the whalers responded by firing high-powered hoses to keep the Sea Shepherd vessels away, the institute said in a statement.
Here they are clearly aiming something at the ship.
the ship had a right to defend themself from these terrorists.