About four miles off Florida’s Gulf-hugging Route 98, between Carrabelle and Apalachicola, a slender barrier island sits mostly untouched by the high-rises and traffic that define so much of coastal Florida. That’s St. George Island — 22 miles of white sand, sea oats, and one working lighthouse that once guided merchant ships along the Forgotten Coast. This guide covers everything you need to plan a trip: what the island is known for, the best t…