Produced in 1999 but not broadcast until 2001.
The film omits Winnie Roach, the third swimmer who attempted the crossing of Lake Ontario at the same time as Flo Chadwick and Marilyn Bell. Like Chadwick, Roach also dropped out of the race early on.
From Wikipedia: Florence May Chadwick (1918 - 1995) was an American swimmer known for long-distance open water swimming. She was the first woman to swim the English Channel in both directions, setting a time record each time. She was also the first woman to swim the Catalina Channel, the Straits of Gibraltar, the Bosporus (one way), and the Dardanelles (round trip).
Epilogue: "In the following years, Marilyn Bell went on to swim both the English Channel and the Juan del Fuca Strait. At 19, she retired at the height of her fame, married, and became a school teacher and a mother of four. She still loves to swim."