Jacques Cousteau opened up the undersea world as no one has done before or since. But not generally know is the fascinating and compelling individual behind the acclaimed television personality. With the cooperation of many of Jacques Cousteau’s collaborators, friends, and family, Brad Matsen gives us the first full picture of this remarkable life. Here is Cousteau working for the French resistance during World War II (for which he received France’s Croix de Guerre); developing—and risking his life to test—the regulator that made scuba diving possible; running the world’s largest scuba equipment manufacturing firm; becoming a legendary catalyst of the worldwide environmental movement; starring in The Undersea World of Jacques Cousteau and in hundreds of documentaries; and publishing more than fifty books. And here is the widowed Cousteau marrying his longtime mistress—forty years his junior and the mother of two of his children—kindling a bitter family feud that continues to this day. Vividly conveying the people, the adventure, the science, and the lure of the sea that shaped Cousteau’s life, Matsen paints a luminous portrait of a man who profoundly changed the way we view, and treat, our planet.