Utila is the smallest of Honduras' major Bay Islands, after Roatán and Guanaja, in a region that marks the south end of the Mesoamerican …Utila is the smallest of Honduras' major Bay Islands, after Roatán and Guanaja, in a region that marks the south end of the Mesoamerican Barrier Reef System, the second-largest in the world. It has been documented in history since Columbus' fourth voyage, and currently enjoys growing tourism with emphasis on recreational diving and is known as one of the world's best dive locations.