A 40-foot catamaran found drifting off Australia's Great Barrier Reef had its sails up, engines running and food on the table, but no crew, officials said Friday after launching a massive search for the missing men.

A coastal patrol aircraft spotted the vessel Kaz II on Wednesday but rescue workers only reached the boat early Friday, confirming there was no one aboard.

Officials said they were puzzled by what they found.

"They got on board and said the engine was running, the computers were running, there was a laptop set up on the table which was running, the radio was working ... and there was food and utensils set on the table ready to eat, but no sign of the crew," said Jon Hall, a spokesman for Queensland state's Emergency Management office.

"It was a bit strange," he said.

The vessel's emergency beacon and three life jackets were still on board, along with a dinghy.

The catamaran's sails were up, but the headsail was "shredded," according to Warwick Bracken of the Australian Maritime Safety Authority.

There was no indication of any other damage, or that the vessel had capsized.

Queensland police confirmed that three men were missing, and that a massive sea and air search was under way Friday from Airlie Beach to the northeastern city of Townsville.

Media reports said the missing men are skipper Derek Batten, 56, and two of his neighbors — brothers named Peter and James Tunstead, ages 69 and 63, from Western Australia state's capital, Perth.

Police would not confirm their identities.

The men had set out from Airlie Beach on Sunday, and were planning to sail around northern Australia to Western Australia state, according to Sharon Davidson of the Australian Maritime Safety Authority.

James Tunstead's daughter, Keryn Grey, said her family was hoping the men were in a dinghy and that the catamaran had drifted away.

"That's what we are hoping, that they forgot to anchor it (the catamaran) and it's drifted off — the three idiots — and (they have) not been able to get back to it," Grey told the Seven Network television.

Grey said the trip was supposed to take the trio six to eight weeks.

"They were just going to stop every night, anchor close to shore all the way back around the top and down the coast," she said. "It was going to be their trip of a lifetime."

The men are reportedly keen fishermen.

Nine planes and two helicopters were searching an area spanning about 700 nautical miles (805 miles), along with four volunteer rescue boats, police and maritime officials said.

Marine police were towing the vessel back to shore for further investigation.

Greg Connor, a forecaster with the Bureau of Meteorology, said the sailors would have faced moderate southeasterly winds of about 22 mph, typical weather for this time of year.

"It would have been excellent sailing conditions," he said. "There's no reason to believe this is a weather related incident."