The anti-whaling mission of the badly damaged ship Brigitte Bardot is over.
The Sea Shepherd's scout vessel was escorted into Fremantle by sister ship the Steve Irwin on late Thursday afternoon.
A wave hit the Brigitte Bardot on January 3 in rough waters in the Southern Ocean, cracking the port side pontoon about 370 kilometres off Fremantle.
All but three crew members were evacuated.
The vessel is undergoing repairs, expected to take three to four weeks and cost about A$200,000.
Paul Watson, the captain of the conservation group's flagship the Steve Irwin, said the Brigitte Bardot had done its job in scouting out the location of Japanese whaling ships.
It would be available for its campaigns to protect sharks in the spring.
He said the small ship was adequate to handle the rough conditions of the Southern Ocean.
"Nothing is really appropriate down there," Captain Watson said.
"It is pretty hostile conditions.
"Any vessel can be hit by a rogue wave and this is what has happened."
The Steve Irwin was to leave Fremantle today to rejoin the Bob Barker, which is expected to take about seven days.
- AAP
It's understood a NZDF aircraft and multiple helicopters are involved.