After spending 81 days at sea, anti-whaling activists The Sam Simon finally returned to Sea Shepherd's Ship Operations Base in Williamstown, Victoria.

During their campaign, Operation Relentless, to stop whalers from killing humpback whales the activists experienced a number of skirmishes with Japanese harpoon ships in the Antarctic Ocean.

It was their 10th campaign against the killing of the sea animals. Captain Adam Meyrson said Japanese whalers killed 100-200 whales, but they successfully saved humpback whales.

He added that it was one of their best campaigns ever. He said he was feeling good to have participated in such a successful and effective campaign to save humpback whales.

Speaking on the topic, he said, "It feels good to participate in such a successful and effective campaign. It has been an honour working with such dedicated crew of all our ships and with the other Captains, Peter Hammarstedt and Sid Chakravarty."

Sea Shepherd campaigners have also urged the Federal Government to fulfill its promise to examine whaling operations on the water.

Bob Barker and Steve Irwin - two of Sea Shepherd's ships - will keep an eye on Japanese whalers during the rest of the whaling season that ends in mid-March.