Netflix is developing a feature film based on Jessica Watson’s sailing memoir “True Spirit,” with Sarah Spillane on board to direct.

Watson became the youngest person to sail solo, non-stop and unassisted around the world in 2009, surviving seven knockdowns while at sea for 210 days on a 33-foot vessel. She returned Sydney, Australia, three days before her 17th birthday. Watson said she didn’t consider herself a hero and described herself as an “ordinary person, who had a dream, worked hard at it and proved that anything really is possible.”

“It’s quite humbling to have Netflix bring my story to life,” Watson said. “I hope that the film inspires people around the world to try sailing and to also pursue their own adventures. I’m thrilled that it will be directed by Sarah and supported by such a strong production team.”

Spillane, whose directing credits include “Around the Block” and “This Life,...