Oscar-winning movie star Jennifer Hudson got her start at sea; world-famous opera singer Fredericka von Stade sets sail this year; the Boston Symphony Chamber Players and the Royal Academy of Dramatic Art step on board as well, and The Second City, the comedy club that launched the careers of America’s funniest people, from John Belushi, Bill Murray and Martin Short to today’s hottest stand-up and TV stars, has audiences rolling in the aisles, even when the ship’s not moving...