I always found it hard to find detailed information on his wartime activities. I know he said he was active in the French Resistance but I think his Croix De Guerre was awarded for actions against the Italian resistance while he was with the Vichy navy. I can't find real good info on that though. His aqualung prototype was definitely built in Paris vicinity in 1943 so that smells fishy to me too. His brother went to prison as a collaborator. What do the more knowledgeable members here think of him?
This maybe of use. It's a commerative edition of Historical Diver on Jacques Cousteau which contains an article called The Early Years. Some interesting looking stuff. He did serve in the French navy and took part in the bombardment of Genoa in 1940. http://aquaticcommons.org/15001/1/Historical_Diver_13_1997.pdf