A man who vanished from a prominent Tasmanian tourist site more than 15 years ago has been declared dead by a coroner.
NSW tourist Joao De Ornelas, 76, disappeared near the Tahune Airwalk near Geeveston on March 3, 2010, while on a bus tour of Tasmania with his wife and a friend.
Mr De Ornelas, who was blind in one eye and had limited function of one arm, had split off from his tour group and was last seen about 2pm walking down a path away from the airwalk, coroner Madeleine Wilson noted in her report published on June 25.
"Mr De Ornelas was reported missing to staff of the Tahune Airwalk shortly after 2.30pm," Ms Wilson noted.
The Tahune Airwalk is located about 88 kilometres south of Hobart, and features a 600-metre elevated walkway set among treetops.
It is a popular tourist destination, offering mountain views as well as views along the Huon and Picton rivers.
After staff failed to locate the missing man, the search escalated with members of Forestry Tasmania and later Tasmania Police joining efforts.
"During the evening, further police and State Emergency Service searchers arrived from Hobart," the report read.
"Search crews scoured the scene until midnight before retiring for the night."
The operation continued for another four days, but no trace of Mr De Ornelas was ever discovered.
According to the assessment of survival expert Dr Paul Luckin, Mr De Ornelas' prospects were diminished by his advanced age, poor eyesight and lack of protective clothing against cool overnight temperatures.
"In Dr Luckin's opinion, Mr De Ornelas had no chance of survival by Monday morning, 8 March, 2010," Ms Wilson wrote.
"Mr De Ornelas likely died of hypothermia, exhaustion and dehydration contributed to by his limited ability to fend for himself because of his poor eyesight and limited arm function, lack of protective clothing in a cold environment and lack of water."
The coroner noted that investigations by the missing persons unit had found no indication of "administrative activity" that would indicate Mr De Ornelas was alive.
"There is, for example, no evidence he has accessed his bank accounts or engaged with government agencies since his disappearance."
She concluded that Mr De Ornelas died in early March, 2010.