She saw her husband come off his single ski as he crossed the wake and described it as a "normal, unremarkable crash".
The boat turned back but while those on board could see the ski they could not see the man.
They signalled a nearby boat for help and two people got in the water to search, but could not find him.
Police, Coastguard and a rescue helicopter began a search. The Police National Dive Squad joined the search the next day but the man was not found. On February 14, the man's body was located using a radial sonar on the lake bed, in 30m of water.
A post mortem reported the cause of death as "no anatomical cause of death identified".
Dr Tim Sutton noted the man was an experienced waterskier of apparent good health.The examination found no conclusive evidence of a medical event and there was no evidence alcohol or drugs contribute to his death.
The diagnosis of death by drowning was made by exclusion of other causes.
Fredericksen said there was nothing connected to the boat, the manner of driving or the lake conditions that appeared to contribute to the incident.
He said it was possible the man may have been winded when he hit the water, which would explain why he was unable to bring himself to the surface.
When asked if he would have been expected to surface naturally had he been wearing a lifejacket, Fredericksen replied "yes".
The man's wife, who was in the public gallery with other family members, said in the days before the incident her husband had been to three different shops looking for a lifejacket but had been unable to find one in his size.
"What a tragedy", the coroner remarked.
Bain reserved his findings but said he hoped to get them out quickly.
Addressing the press, he said with it being weeks from Christmas and the busy boating season on the lakes it was important to get the safety messages out.
