The times listed are ships times. How that will relate to the time in Cozumel depends on whether the Captain adjusts the ship time. Sometimes they do and sometimes they don't. On our trip this past Christmas on the Wonder the Captain adjusted our time ahead by an hour after we departed CocoCay to that we would match St. Marten and St. Thomas and then it was adjusted back after we left St. Thomas. This doesn't always happen and you will be told on board.