CAGLIARI, Italy — Nearly 500 passengers, including eight with broken bones, disembarked from the Grand Voyager cruise ship in Sardinia on Tuesday, a day after it was battered by a storm in the Mediterranean Sea.The Voyager lost communications and most of its power Monday as it was pummeled by gales and waves up to 15 meters, or nearly 50 feet, high while en route from Tunisia to Barcelona."It was like being on a roller coaster," a Spanish passenger said.