A Cambridge-born Waterloo resident attempted to set a new record on Tuesday.
Tom Bartlett, 72 years old, began his swim from Niagara-On-The-Lake just before 12:30 a.m.
He first set his sights on the feat in 1954, when Marilyn Bell completed the first successful swim.
Training for years, he originally wanted to begin the swim earlier, but bad weather got in the way.
His team told CTV that the water Tuesday was calm and warm.
The swim to Marilyn Bell Park in Toronto is expected to take about 24 hours, meaning he was expected to finish around midnight.
The previous person to complete the swim was 66 years old.
