Odd Ones by Janet Lambert

At seventeen, Josie Campbell feels everything in her life is moving too fast for her. Unsure of what to do, Josie leaves Indiana to travel to Sea Haven Island to stay with a friend of her older sister Sandra. There she writes the story of her family's vagabond life, The Odd Ones. And there she meets a kindred spirit, Nils, who has also dropped out of college to run his family's boatyard.