If Star Island is Miami’s flashy red-carpet hotspot, La Gorce Island is the quiet, ultra-private retreat right next door. It’s guard-gated, palm-lined, and known for a calm, understated kind of luxury. Sitting in the middle of Biscayne Bay, the island has just 59 homes — 33 of them true waterfront with space for serious yachts. Built in the 1920s and named after National Geographic explorer John...