Jacques Cousteau was a French spy while serving in the French Navy.

Cousteau graduated in 1933 from the Ecole Navale in Brest, the national naval academy of France. In 1937, he married Simone Melchior, descended from three generations of French admirals. The couple had two sons: Jean- Michel, born in 1938, and Philippe, born in 1939.

During the Second World War, Jacques served as a spy for the Allies within Vichy France, while his brother, Pierre- Antoine, became a German collaborator who wrote racist editorials against Jews, shrill denunciations of the resistance, and apologetic stories of Nazi actions. After the war, a French court condemned Pierre to death for his wartime activities. Jacques' display of loyalty to his collaborationist brother, even testifying at the trial in his formal officer's uniform bearing several war medals, haunted him throughout his three-decade-long naval career. Admirals informally labelled him as undisciplined and suspect. Cousteau would be given responsibilities, but he remained a captain while all his academy classmates who survived the war earned further advancement.

With financial support from a wealthy British seafarer, Cousteau purchased and refurbished a war-surplus minesweeper in 1950, and christened it Calypso. That ship became famous throughout the world for its role with documentary films, industrial projects, and undersea habitations.

https://www.independent.co.uk/incoming/obituary-jacques-cousteau-5561377.html