In “The Last of the Sea Women,” an extraordinary band of feisty grandmother warriors wage a spirited battle against vast oceanic threats. Often called real-life mermaids, the haenyeo divers of South Korea’s Jeju Island are renowned for centuries of diving to the ocean floor – without oxygen – to harvest seafood for their livelihood. Today, with most haenyeo now in their 60s, 70s, and 80s, their traditions and way of life are in imminent danger. But these fierce, funny, hardworking women refuse to give an inch, aided by a younger generation’s fight to revive their ancestral lifestyle through social media. Peering into what drives Haenyeo young and old, this moving documentary zeroes in on their tight-knit friendships, savvy independence, and infectious sense of empowerment, unfolding into an uplifting tale of women taking on world powers to protect their beloved ocean and inspiring a new one generation.