I have seen whales in the open sea, I've been whale watching, and saw some orcas.
But I don't get why the Japanese aren't packing heat.
For what reason? Nothing the anti-whaling folks done would allow a response with deadly force under international law.
But what's to stop the whalers from shooting a big hole in the other boat's hull?
Fear of jail? International waters does not equal no laws. The world's Navies take a dim view of open warfare between ships at sea. If the Green peace'ers are US citizens, I am fairly certain that they can sue in US courts.
Admiralty law is decently well settled law and corporations are generally risk adverse and whalers don't want to eat up their profits on stupid avoidable expenses.