Almost five decades on, a coroner has been unable to shed any further light on the tragedy which has been dubbed one of Australia's biggest sailing mysteries.
Lawrence Corkhill, 61, son Jeffrey Corkhill, 32, Charles Davies, 35, Ian McIndoe, 27, and David Symes, 37, were delivering the 37-foot Charleston to Sydney for the Southern Cross Cup.
Charleston left the Royal Yacht Club of Tasmania in Hobart on December 8 and picked up Lawrence Corkhill further up the island the next morning.
The crew's last radio contact was at 6.29pm on December 10 off Flinders Island heading into Bass Strait.
They failed to arrive in Sydney on December 13 as planned and were reported missing.
More than 20 aircraft, including three Royal Australian Air Force planes, were involved in a multi-day search covering 140,000 square miles.
It was suspended on December 19 but resumed two days later under direction from then-prime minister Malcolm Fraser.
Family and friends also chartered aircraft to comb the seas but no trace of the crew or the Charleston were found.
In findings published on Friday, coroner Madeleine Wilson ruled the men likely drowned on December 10 and said her investigations didn't uncover any new information.
"Family members of each of the missing men swore affidavits that they were each happy, healthy and financially secure," she said.
"I have no reason to suspect that the deaths were anything other than a tragic accident that occurred at sea, in circumstances which are unable to be ascertained."
Dennis Leitch, who was sailing Chaos about 30 miles southeast of Charleston on December 10, said conditions on the day were "atrocious and quite frightening".
There were gusts up to 55 knots and 20ft waves that knocked his yacht sideways, he said.
Charleston, considered to be state-of-the-art, was fitted with up-to-date navigation equipment and carried a new lifeboat, flotation devices and flares.
The wooden and fibreglass hull yacht had passed all required testing and complied with safety requirements of the prestigious Sydney to Hobart race.
Mr Davies, who was skipper, was very safety conscious and was known to follow recognised procedures including the provision of position reports.
Ms Wilson said coronial investigations were launched when inquiries in 2022 revealed the incident had not been reported to the coroner.
Laws implemented in 1978 extended the jurisdiction of the coroner and would have allowed investigations into the deaths of Jeffrey Corkhill, Mr Davies and Mr McIndoe.
However no coroner was notified at the time, Ms Wilson said.
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