On the island of Man-Jae in Korea, three elderly women spend their dying days diving into the ocean to harvest seafood with nothing but a rusty knife. They are “haenyeos”— “sea women” —and there are no heiresses to their millennium-old tradition. ENDLINGS is a real estate lesson from the last three remaining “haenyeos” in the world: don’t live on an island. Unless it’s the island of Manhattan…