The conservation group Sea Shepherd is heading for Antarctica on another anti-whaling campaign.
Sea Shepherd is sending four vessels south this summer. One of them, the Bob Barker, was due to set sail from Wellington at 7am on Saturday.
In December, a United States court ordered Sea Shepherd to stay at least 450 metres away from Japanese whaling ships.
But the Bob Barker's captain, Peter Hammarstedt says they will do whatever it takes to get in the way of the Japanese fleet and stop the whaling season early.
"We want to basically find the japanese whaling fleet as early as possible, shut them down and hopefully cause them to cast their whaling season.
"We've been successful with that in the past - in fact, last year we prevented the whaling fleet from taking 763 whales. and this year we're trying to make sure that the whaling fleet does not take a single whale."
Mr Hammarstedt says thousands of people were taken on tours of the Bob Barker during the past month while it was berthed in the New Zealand capital.
Japan claims that its whaling programme is for scientific research.