BELLS BEACH, Australia >> Kelly Slater caused a stir in the surfing world on Thursday when the 11-time world champion suggested in an Instagram post that the Bells Beach event in Australia might be his last before retiring.

What still hadn’t been determined was whether Slater was playing a late April Fools’ Day prank from the event about 60 miles southwest of Melbourne.

The 43-year-old American said in the post that "big decisions in life don’t come easy and it’s taken a lot of quiet time and personal introspection to come to this conclusion.The (hashtag)RipCurlPro was the first event I surfed on tour and it’s fitting that this will be my last @wsl. There are too many people to thank and memories to go over but here’s to hoping I can pull a rabbit out of the hat and win one last event this week."

But Slater added later in the post: (hashtag)"HappyApril1stEveryoneBackHome." Slater’s post was sent on April 2 in Australia, but it was still April 1 in the United States.

Two television commentators on Thursday’s live telecast from Bells Beach were divided over the authenticity of Slater’s post, one thinking it was part of an April 1 prank, the other thinking it might be true.

Slater is through to the third round at Bells Beach, but was not expected to compete Thursday due to a delayed start because of poor morning surf conditions.

Adding credence to the possible retirement was Slater’s growing list of activities away from the beach. Several surfing magazines on Thursday reported that in the coming months he would be busy as the new majority owner of a surfboard company, with the launch of his yet-to-be-seen clothing brand and the development of a film documentary on surfers smuggling drugs.

And not every April 1 announcement can be considered a joke. On April 1 last year, Slater announced what turned out to be a bona fide split from longtime sponsor Quiksilver.

The Cocoa Beach, Florida-born Slater began surfing professionally in 1990 and was ranked first on the ASP World Tour 11 times — the first time in 1992 and the most recent in 2011.

Slater, who has played off a golf handicap as low as scratch, has said he plays about 150 rounds of golf a year. He has hinted at making an attempt to play on the Champions Tour when he is eligible at the age of 50.

Earlier this week, he was announced as a member of the Fred Couples-captained U.S. team to play in a Ryder Cup-style celebrity event in Dubai from April 22-24.