Sure, her granddad's name is practically synonymous with the ocean, but that doesn’t mean Alexandra Cousteau had to follow in his flippers. She just wanted it that way.Calling Alexandra Cousteau “grounded” wouldn’t be quite right. Yes, the 36-year-old granddaughter of the legendary French underwater explorer Jacques Cousteau has her priorities in place. As the founder of Blue Legacy, an initiative based at Washington, D.C.’s Ocean Foundation and dedicated to raising awareness about global water issues, she’s a leading expert on the subject. She and her husband, a German architect, are devoted parents to their infant daughter, Clementine, carting her along on business trips to the Middle East and South America with a suitcase of diapers in tow. But “fully submerged,” or maybe “lifting off,” would probably be more to the point. For Cousteau is constantly on the move, boarding one sea- or aircraft or another to reach some far-flung destination in order to learn more about the environment and the threats it faces.