In “The Last of the Sea Women,” an extraordinary group of fiery warrior grandmothers wages a fierce battle against vast ocean threats. Often referred to as real-life mermaids, the haenyeo divers of South Korea’s Jeju Island are renowned for having spent centuries diving to the bottom of the ocean—without oxygen—to harvest seafood for a living. Today, most haenyeo are in their 60s, 70s, and 80s, and their traditions and way of life are in imminent danger. But these fierce, funny, and hardworking women refuse to give up an inch, aided by a younger generation’s fight to revive their ancestral way of life via social media. Exploring what motivates haenyeo young and old, this moving documentary focuses on their tight-knit friendships, savvy independence, and infectious sense of empowerment, unfolding in an uplifting story of women taking on global powers to protect their beloved ocean and inspire a new generation.