The 23-year-old driver from Canada was following a GPS route at the tip of the Bruce Peninsula – in the south of the province – an area she did not know well. At a certain point after midnight, she lost her way and drove down a steep boat launch into Lake Huron.
A woman following her car’s sat nav on a foggy night took a wrong turn and ended up driving into a lake.
The woman was able to roll down a window, grab her handbag and swim 30 metres to safety, as her car filled with water.
Local police said the way the harbour’s boat launch is built means a wrong turn taken on a rainy night would come as a shock.
“She would have been driving on the road, and then all of a sudden just dropped and hit water,” Constable Katrina Rubinstein-Gilbert told the Canadian Press.
The driver sought help at a nearby hotel as her red Toyota Yaris sunk completely.
Ms Rubinstein-Gilbert said the driver was well, if “a little embarrassed”, and would not be charged.
The incident, which took place last Thursday, did not involve alcohol. The vehicle was retrieved from the lake on Friday morning.
The driver has denied all media requests.
One in seven drivers in the UK admit to making risky manoeuvres to correct sat nav mistakes, according to a survey by road safety charity Brake.
And one in 14 say they have narrowly avoided an accident after being distracted by their GPS system while driving.