Three members of a South Australian family who mysteriously vanished without trace five years ago, triggering an extensive ocean search, were the victims of a deadly boating mishap, a coronial inquest has concluded.
In findings handed down today, Deputy State Coroner Anthony Schapel dispelled suggestions there was anything "suspicious" about the disappearance of the Vandepeers, noting no "unexplained bank transactions" in the days after their presumed drownings.
Annette and Len Vandepeer, both 56, and their son Douglas, 27, went missing on December 12, 2016.
The trio from Keilira, near Kingston in SA's south-east, have not been seen or heard from since that date, when a boat — believed to have had them on board — was towed to the water by a Landcruiser and then launched from Cape Jaffa marina about 10:30am.
Despite being abundantly equipped with safety equipment, and being in good condition, the seven-metre aluminium vessel has never been recovered — although some equipment on board was later found to have washed ashore.
The disappearance of the Vandepeers shocked the local community and prompted a lengthy land, aerial and marine search that continued into the following month.
In January 2017, SA Police's Water Operations Unit conducted underwater sonar searches in an effort to locate the boat.
But a definitive explanation eluded authorities, and the deputy coroner pursued several lines of inquiry during an inquest.
Mr Schapel concluded the trio had died as "a result of exposure to the sea" when their boat sank, even though the cause of its sinking remains unexplained.
While aspects of the matter remain inconclusive, Mr Schapel rejected alternative explanations, finding there was "no evidence to indicate" they "did not die as a result of a marine incident".
"There have been no unexplained bank transactions in connection with the Vandepeers after [December 12]," Mr Schapel wrote.
"[Their] medical histories are unremarkable. There was no history of mental health issues.
"I understand that there is no evidence of outgoing calls or other communications made from any of the Vandepeers' phones after 12 December 2016 or answered calls after that date on those phones."
Mr Schapel noted that the boat in question — a 1992 model Quintrex Yellowfin — was owned by Len Vandepeer's brother Angus, who lived on the same farming property as his brother and was planning to sell the boat.
The day before, Len "spoke to his brother Angus and asked to use the boat to go sightseeing before it was sold", the inquest findings state.
"Len told Angus that he wanted to inspect the damage that had been caused around the Cape Jaffa area due to recent weather. He also wanted to see the Margaret Brock Reef and to possibly fish."
CCTV from the marina the following day shows a Landcruiser — believed to be Len Vandepeer's — towing a boat, the inquest found.
Mr Schapel concluded the boat had subsequently sunk, but acknowledged the cause was unknown.
"As to why the boat has never been found can only be the subject of speculation.
"Police have maintained contact with the surviving members of the Vandepeer family and have received no information that would suggest that Lennel, Annette or Douglas were alive at any time after 12 December."
Mr Schapel concluded that each had died "as a result of exposure to the sea".