Divers off south-east Queensland's North Stradbroke Island have been treated with a rare and spectacular sighting — a whale shark.

The five-metre long juvenile male was spotted off Point Lookout on Sunday.

University of Queensland marine biologist Dr Kathy Townsend said it was only the second confirmed sighting of a whale shark off Straddie in about 10 years.

"Normally whale sharks you find really commonly on the west coast, so places around Ningaloo and things like that. However, here on the east coast we very rarely see them," she said.

"I think the last time we spotted one at Straddie was somewhere between five and 10 years ago.

"When they do see them, they generally just see them in passing, but this particular youngster spent at least three hours today in the water with divers."

This is only the second confirmed sighting of a whale shark off Straddie in about 10 years. ( Paul Sorensen: User submitted )

Diver Chris Atkins said it was an exciting moment.

"Just amazing that whale shark. That's four times this morning I've seen him. Just fantastic on the east coast of Australia," he said.

Dr Townsend said she believed something different was luring the plankton-eating creature closer to shore this year.

"The difference this year is something has changed with the currents that encourage not only the whale sharks, but we've also had manta rays hanging around unseasonably long this year," she said.

"So, there's something that's going on that's encouraged them to come much closer to North Stradbroke Island than we normally see them.

"It wouldn't surprise me a great deal if the plankton biomass was the thing that was also encouraging the whale sharks to also come into this region, because if there's a lot of food around they will actually come in and seek it out."