Ten Thousand Islands (Doc Ford) by Randy Wayne

Doc tripping is a little funny, and all in all this requires a huge suspension of belief, but hey it's enjoyable. PW: Ford is finagled away from his beloved fish and his stilt house off Florida's Gulf Coast to investigate the grave robbing of a long-dead adolescent girl who had a remarkable gift for finding archaeological artifacts of a long-gone civilization of Calusa Indians. The centuries-old gold medallion that may have been buried with Dorothy Copeland has mysterious powers--at least, that's what a big Florida developer whose son is being groomed for high political office seems to believe.