Heart: The Marilyn Bell Story -- Film Description:
"Based on the major event in the life of Canadian swimmer Marilyn Dilascio (nee Bell) who, in 1954, was the first person to swim across Lake Ontario. The script chronicles her early training and progress, her relationship with her coaches during that period and her incredible swimming feat: the 21-hour lake crossing. The event began as a race against American swimming sensation Florence Chadwick, and ended as an extraordinary solo performance—after Chadwick withdrew—by the diminutive 16-year-old Bell."
-- DHX Media

Source:
DHX Media. "Heart: The Marilyn Bell Story" DHX Media. http://www.dhxmedia.com/shows/liveaction/heart-themarilynbellstory.html.