An 86-year-old West Tisbury man has been identified by authorities as the person found floating off the coast of Martha’s Vineyard on Monday, officials said. Luciano Rebay was positively identified Tuesday as the man found near West Tisbury Monday morning, Cape and Islands District Attorney Michael O’Keefe said. A fisherman in the area found Rebay’s body and notified the Coast Guard, O’Keefe said. The cause and manner of the man’s death are unclear, but authorities do not consider it suspicious, he said.