Anti-whaling group Sea Shepherd Conservation Society expects more skirmishes with Japanese whalers in the Southern Ocean in the coming weeks.
Another of the group's boats is catching up with the whaling fleet, after a collision on Saturday left a Sea Shepherd vessel Bob Barker with a one-metre long gash in its hull.
Its captain, Paul Watson, says the aim is to position the boats so the Japanese won't be able to carry out any whaling, but he believes more collisions will occur.
The New Zealand Government says both the whalers and protesters need to show restraint, and to operate according to the law, before a tragedy occurs and a life is lost.
