The nighttime portion of the swim is the most difficult, Stephanson said, \The nighttime portion of the swim is the most difficult, Stephanson said, "because it's dark, you're by yourself in the water, and it's cold."

A woman from Belleville, Ont., completed a 26-hour swim across Lake Michigan on Monday, becoming the second person to swim across all five Great Lakes.

"For now I'm really happy to feel I finally completed all five," Paula Stephanson, 30, told CBC News on Tuesday morning from her hotel room in Chicago.

Stephanson started her 55-kilometre swim at Rainbow Beach in Chicago on Sunday evening and reached dry land at Washington Park Beach in Michigan City, Ind., 25 hours and 38 minutes later — at around 9 p.m. CT Monday.

She didn't have the energy to celebrate at the time.

"I was just too tired," she said. "I just wanted a warm bath and a bed to sleep in."

The first person to swim across all five Great Lakes was Vicki Keith, who achieved that feat in 1988. Stephanson credited Keith as the inspiration for her own crossing of Lake Ontario in 1996 at age 17.

For her final Great Lake swim, Stephanson said there was never a point when she thought she wouldn't make it, although there were some major challenges along the way. Near the end, she was swimming directly into the wind.

Night most difficult

"You feel like you're making no progress at all," she recalled.

The nighttime portion of the swim is the most difficult, Stephanson said, "because it's dark, you're by yourself in the water, and it's cold."

Stephanson said during those times, she was literally counting the minutes before sunrise, thinking of the warmth that would bring. At other times, she had a song stuck in her head, or just tried to shut down her thoughts altogether.

A support crew in a Zodiac boat helped keep her going by providing liquids such as Gatorade, soup or hot chocolate and small snacks such as fruit and granola bars at intervals along the way.

When asked what her next challenge would be, Stephanson said she planned to "retire" for a while, and wasn't sure if she would do another lake swim again.