Police on Sunday suspended their search for the crew of a catamaran found drifting off Australia's Great Barrier Reef with sails up, engine running and food on the table, saying there was little chance of finding the three men alive.

Police believe skipper Des Batten, 56, and brothers Peter and James Tunstead, aged 69 and 63, may have been swept off the Kaz II when it hit rough seas last Sunday.

"Unfortunately ... it's supposedly almost a week since they've gone missing. [It's] quite difficult to survive without adequate food or water," rescue worker Phil Dowler told Australian Broadcasting Corp. radio.

Queensland police said in a statement the decision to suspend the air and sea search was "based on expert medical advice, which suggests the men could not have survived this long in the water."

The men sent no distress calls, and their plight was not known until about Wednesday when a coastal patrol plane spotted the catamaran drifting some 95 miles offshore.

Rescuers who boarded the vessel early Friday said it appeared to have been abandoned suddenly. The lights and engines were running, a laptop computer was charging and there was even food and cutlery laid out on the table — but no sign of the crew.

The yacht's headsail was shredded, but there was no other sign of damage. An emergency beacon, three life jackets and a dinghy were found on board.

Police admit they are baffled as to what became of the three men.

"It's certainly very unusual," said inspector Warren Webber. "It seems very unlikely we will be able to say exactly just what has occurred at this point in time."

Investigators who examined the catamaran's global positioning system said it appeared to have been drifting with the wind and currents since Sunday, when the men may have hit rough seas.

But the Bureau of Meteorology has said the crew would have faced moderate southeast winds up to 22 mph, or 20 knots, that day, nothing out of the ordinary for this time of year.

The men reportedly bought the boat in the northeastern town of Airlie Beach and set sail from there last Sunday. The men were planning to sail around northern Australia to Western Australia state. All were experienced sailors.

Fran Tunstead, the wife of James Tunstead, said family members would continue searching for the men even though the police search had been called off.

"They are chartering boats, they are going out looking — maybe in the same spot or down [south] a bit further — and we are going to find them," she told ABC television.