Earlybird whale watchers in Eden have been rewarded with astounding acrobatic displays right in the mouth of the bay in what local operators are calling a "spectacular start" to the season.

Each year the krill-rich waters of the south coast are paradise for whales as they migrate along Australia's east coast towards Antarctica.

But this year, whales have been swimming right into Twofold Bay to feast on schools of bait fish and pilchards.

Ros Butt runs Cat Balou Cruises with her husband Gordon.

She said the whale-watching season began up to a month early this year, with impressive numbers of humpbacks, southern rights and dwarf minkes spotted in the pristine waters of the Sapphire Coast.

"It's a far earlier season than what we generally expect," Mrs Butt said.

"Last Friday we ended up 10 miles offshore and we were surrounded by at least 30 humpbacks which is probably the most we've ever seen and we've been whale watching here for 26 seasons."

Helen and Richard Buckingham operate Freedom Charters in Eden.

Mrs Buckingham said they "haven't hardly had to travel" to find whales to watch this year.

"They've been in the bay, there's been mothers and calves, there's been feeding, there's been lots of activity," she said.

"Usually at this time of the year we're still travelling a bit of distance for them. They've been there for the last three weeks so that's quite unusual."

Mrs Butt said: "The ocean is really alive at the moment."

"The last few days we've had singing whales out there, we've had some very close encounters, where they come around the boat, lie beside you, spy hop," she said.

"Some days we've been out there and we've had pod after pod tail-slapping, we really haven't had a quiet day."

And it's not just the whales putting on a show.

Dolphins, Australian fur seals, Australasian gannets, short-tailed shearwaters and albatrosses have also been spotted in droves in the bay, delighting tourists.

A seal was even spotted hitching a ride on a whale south of Eden by photographer Robyn Malcolm.

But it's the whales which keep tourists migrating down south.

"Eden was named the number one whale watching destination in Australia last year by Australian Geographic and I think it's living up to its reputation," Mrs Butt said.

The whale-watching season runs from September to November.

Eden's Whale Festival is on the first weekend of November.