Daisy Ridley's candid conversation about 'Young Woman and the Sea'

LOS ANGELES -- In the new movie, "Young Woman and the Sea," Star Wars actress Daisy Ridley plays Trudy Ederle, the first woman to successfully swim the English Channel.

The accomplishment earned Ederle the largest ticker-tape parade ever in New York City but has mostly been forgotten by history - even though other sports heroes of that era, like baseball legend Babe Ruth, are still household names a century later.

"I don't even really know American sports that well (but) I know Babe Ruth!" Ridley told On The Red Carpet. "It was pretty shaming to read the script and not know about (Trudy). And I think generally that's been the feeling that people cannot believe that what she did has been lost to history."

Playing Ederle on screen meant months of training with an actual Olympic swimmer for Ridley, whose swimming skills improved dramatically over the course of filming.

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"My first swimming test I tried to swim a 20-meter pool and ended up halfway and said 'I can't do it.' And then thought, 'What have I done?'" Ridley said. "I might have lied on my CV."

For the film's dramatic final swim from France to England, Ridley spent nine days filming in the chilly waters of the Black Sea.

"I think if I wasn't really in the water, you wouldn't have felt the impact of what Trudy did," she said.

Part of Trudy Ederle's success can be attributed to the support she got from her family including her sister Meg. Tilda Cobham-Hervey plays Meg in the film and says bringing that story of sisterhood to the big screen was something special.

"That's the bit in the script that I think really moved me," Cobham-Hervey said. "It's so lovely to be able to celebrate a relationship between women like this, particularly as sisters, two women that are really supporting each other to be the best version of themselves and to challenge sort of the world they've grown up in and what's expected of them, so I found that part really moving, and it was really fun to be able to explore that on screen together."

Watch On The Red Carpet's full interview with Daisy Ridley and Tilda Cobham-Hervey in the video above.

Disney's "Young Woman and the Sea" opens in select theaters Friday. It's rated PG.

Disney is the parent company of On The Red Carpet and this ABC station.