11 HYDRA, Greece, June 9.—(UPD -Mrs. Jacqueline Kennedy sailed to this Aegean Island today on the second stop of her four day escape cruise among the Homeric islands. She was refreshed, delighted and slightly homesick. A quick swim off the beach at Hydra followed a formal greeting by the island's official greeter, a man named Savas who has been studying English but thus far has learned only one word: "Hello." The whole town echoed that "hello" by presenting sparkling faces to America's First Lady. After her swim at Hydra, Mrs. Kennedy went to the luxurious hillside home of John Haramis, professor at the University of Athens, was entertained at a tea by Mrs. Katerina Paouri, wealthy owner of a 200-year-old house on the through Haramis. island, and strolled the town with Mrs.