Officials in Thailand have been especially puzzled that the body of Carmel Brookes has not washed up along the coast, and frustrated that the circumstances surrounding her disappearance have never been fully reported to them.
Ms Brookes, 60, was last seen aboard the yacht Moondancer 2 as she and her boyfriend, prominent marine biologist Dr Gerry Goeden, headed for Phuket.
What experienced yachties cannot understand is why the pair were sharing watches and sailing to Phuket as if they were in a race when most experienced yachtspeople anchor for the night.
According to an article published in Australia today, Dr Goeden explained to Ms Brookes' anxious brother, Bill Heang, that his partner had been on the night watch as the pair sailed Moondancer 2 towards Phuket.
He said he got up to relieve her at 1.30am, off the coast of the Thai province of Trang, found her gone and set off the distress beacon.
''He said two bean bags that had been in the life raft were missing, plus the boat hook, so he believed she had fallen in trying to retrieve them,'' Mr Heang told the 'Courier-Mail' newspaper.
''They were red bean bags and they float but they haven't been found.''
Ms Brookes's body has not washed ashore. Local Thai police and rescue officials along the coast of Trang and the neighboring province of Krabi say this is contrary to experience with previous tragedies at sea and currents in the region where Ms Brookes was lost.
Australian consular officials later called Mr Heang to say they could do nothing more to help because no official report had been made to Thai police about his sister's disappearance, the newspaper reports.
Friends of Ms Brookes have told Phuketwan they accepted Dr Goeden's version of events. But the publication of a new article today after Ms Brookes' disappeared in early February indicates not everyone is at ease.
The Courier-Mail' reported that Lisa Brookes, Ms Brookes' stepdaughter, said the family knew it was unlikely she would be found.
"He (Dr Goeden) rang me and said 'Lisa, I have some bad news to tell you'," she said. "He started crying and said, 'I've lost Carmel overboard'. He gave me a number, said he was out of credit and hung up."
Lisa said she tried to call him back but the phone number did not work.
The Courier-Mail was unable to contact Dr Goeden, who is believed to still be at sea.
According to the Courier-Mail, Dr Goeden's first wife, Ellen Goeden, died in January 1984, in what friends described as a "tragic accident".
A newspaper report at the time said a 37-year-old woman was walking in the Barron Gorge, north of Cairns, when she slipped while crossing a waterfall, falling 10 metres to her death.
A Missing Persons Unit Detective in Brisbane, Senior Sergeant Damien Powell, confirmed they were looking into Ms Brookes' disappearance.
"We are assisting the Department of Foreign Affairs and Interpol in their investigations," he told the newspaper.