Daisy Ridley battles jellyfish and the patriarchy with equal pluck and aplomb in “Young Woman and the Sea.”  

Ridley stars in this compelling biographical drama as Trudy Ederle, the first woman to swim across the English Channel. Ederle accomplished this feat in 1926—nearly a century before the open-water swimming triumph depicted in last year’s Oscar-nominated “Nyad,” to which comparisons are inevitable. For one thing, sports nutrition has come a long way since then. No one was lowering nets full of tea and fried chicken down to Diana Nyad as she made the arduous 100-mile journey from Cuba to Florida. 

That’s one of the most fascinating and frustrating elements of director Joachim Rønning’s film, based on sportswriter Glenn Stout’s book of the same name: The way in which the men in charge of this sport fundamentally misunderstand what Ederle and other female athletes need to train, compete and thrive. Also, they simply don’t care. Mostly, they’re downright hostile, even to Olympians. But as women, we’re resourceful, and Ederle consistently finds a way. Her quick wit and a strong sense of self buoy her when others underestimate her; the same fierce spark we saw in Ridley as Rey in the last three “Star Wars” movies burns brightly here, as well. 

“Young Woman and the Sea” is a worthwhile film for other young women to see, especially if they’re involved in sports. But its themes of daring and perseverance should resonate with anyone who’s ever gone after a goal. Rønning has found a solid balance here: He’s made a feel-good sports film that’s stirring without being schmaltzy, one that dips into genre tropes just enough to provide familiarity and structure.  

It’s also a thrilling adventure. The Norwegian filmmaker, whose Oscar-nominated “Kon-Tiki” from 2012 probably prepared him for the challenges of shooting in the water, makes us feel like we’re slicing through the waves alongside Ederle. Her passage across a bright-red jellyfish field is particularly harrowing, and the depth of her fear is evident, even in the dark of night, once she’s forced to go it alone in the shallows outside Dover. Cinematographer Oscar Faura (“The Impossible,” “The Imitation Game”) vividly depicts a variety of environments, from Ederle’s cramped, working-class upbringing to the sun-dappled vastness of the English Channel.  

But when we first see Ederle, as a sickly child in 1914 Manhattan, she’s on the brink of succumbing to measles. The adorable Olive Abercrombie plays her as a spirited tween who overcomes this physical adversity to pursue her dream of learning to swim, even though that’s something girls just don’t do, as her traditional, German-immigrant father (Kim Bodnia) repeatedly scolds her. Ridley takes over as a teenager, with Tilda Cobham-Hervey (Helen Reddy in the biopic “I Am Woman”) playing Trudy’s older sister, Meg. (They’re well-cast as sisters and share a warm chemistry, but both actresses look too mature to be playing characters who are so much younger, which is distracting for a while.) Their elegant and headstrong mother (Jeanette Hain) insists that both daughters should become swimmers, which inspires the obligatory training montages in a tiny, indoor pool, led by the amusingly no-nonsense Lottie Epstein (Sian Clifford).