Police say the couple were on a catamaran that capsized yesterday around the noon hour, south of the Burlington Canal lift bridge.
The 34 year old man fell off the craft and when his companion, 29 year old woman tried to rescue him, the boat flipped over and she ended up in the water as well.
Police say the woman had a VHF radio attached to her life jacket and made a mayday call from the water.
The Hamilton and Halton Marine Units responded and found the man, who was also wearing a life jacket, about 1.5 miles offshore.
Police say he had had some signs of mild hypothermia but was not injured, after spending 1 hour in the 18°C water.
Both the male and female were brought to shore and assessed by paramedics.