They would not sink boats. Even for some of the largest fishing boats, the marine would just sent a larger military boat and board it, transport the sailors to land and give them to the police for dealing with. The fishing boat would be confiscated.
Actually sinking of boats is highly unnecessary and not something people do unless the other boat has cannons and rockets, which a fishing boat is unlikely to have.
> unless the other boat has cannons and rockets, which a fishing boat is unlikely to have.
Well, you say that, but they have been known to use bombs.
> Sea Shepherd said fishermen threw rocks that broke the ship’s windows and tossed gasoline bombs that briefly ignited a fire on the Farley Mowat’s deck. [0]
Actually sinking of boats is highly unnecessary and not something people do unless the other boat has cannons and rockets, which a fishing boat is unlikely to have.