Event organisers will make another call on when to commence competition on Thursday at 6.45am AEST.

"It is pretty flat so we've called today off," Kieren Perrow, WSL Competition Director, said.

"Pretty confident we will be going tomorrow... If the wind does come up at all, I am sure we should still have fun-sized waves in the four-to-six-foot range."

Once the action does get under way, American teen Caroline Marks will be among the favourites after her season opening victory on the Gold Coast just nine days ago.

Marks was still eight years from being born when Kelly Slater rang the iconic Bells Beach trophy in 1994 for the first time.

Now the two Florida surfers are among the star attractions at the Rip Curl Pro.

Marks, 17, is the new phenomenon of women's surfing and Slater, 47, is the legendary 11-time world champion and four-time winner at Bells Beach.

In her debut at the event last year, Marks narrowly lost to eventual winner Stephanie Gilmore in the semi-finals.

"She's such a talent; I've been calling her to win an event for well over a year now," Slater said.

"I see her as a favourite.

"Now she knows she can win, it's going to open a floodgate for her and I see her as a realistic threat for the world title this year."

By contrast, Slater is coming off a second-round elimination at the Quicksilver pro and is unsure whether this will be the last time he competes at Bells Beach.

"I try not to think about that too much. I really had that on my mind on the Gold Coast," he said of potentially competing at Bells for the last time.

"I wanted to try to avoid that pressure but it was just there.

"So, look, if it's my last time surfing Bells, so be it - it may be.

"But I've never won a single contest thinking 'this could be my last time, I've got to do this', that's not the approach.

"I have to be mindful of that."

The window for the Rip Curl Pro runs until April 27.

Australian Associated Press