A jet ski rider missing off Queensland's Sunshine Coast may have been taken by a shark, police fear.
Luke Howard vanished as he and a mate made a desperate dash for the shore after their vessel took on water yesterday afternoon.
Choppers, boats and drones are searching for the missing man who was in the water and being towed behind the stricken craft when he disappeared.
The 35-year-old and his friend were fishing near Mudjimba Island when the emergency forced them to head for shore.
Senior Constable Mark Vickers says Mr Howard stripped off his life jacket to search for the leak.
"The missing person got off the jetski to check the bungs and find out why it was taking on water," he said today.
"He was unable to get back on the jet ski."
As the jet ski became unstable, the two men made for shore and Mr Howard complained of being tired.
"When the jet ski has arrived on the beach, the missing person was no longer with the jet ski," Constable Vickers said.
He said police could not rule out that the man had been taken by a shark.
"It's possible, we just don't know what has happened."
Visibility for the search has been good and the sea flat, eroding hopes he might have survived.
"We would have expected to have a result almost straight away in those conditions considering we had all the resources poured in from the start," Constable Vickers said.
"It's probably more of a recovery now but we will keep searching until all hope is lost."
Police have spoken to the man's distraught friend and family who have gathered on the beach near the search area desperate for news.
Friends say Mr Howard, a triathlete, is fit and are hoping his physical strength might have allowed him to survive.
The search will continue until last light and is expected to resume tomorrow.