The California coast was shrouded in fog the morning of 4th July 1952. Twenty one miles to the west, on Catalina Island, a 34 year old woman waded into the water and began swimming toward California, determined to be the first woman ever to swim the strait.

She was Florence Chadwick.

She had already set the world record for swimming the English Channel in 13 hours 20 minutes, and was the first woman to swim it in both directions.