Greetings
If it is an expensive camera, the gentlemen had probably declared the loss in the police station or in the lost and found facility close to the beach.
So next time you go there for a swim, drop by the police station, BTW it looks like military flying suite.
Check if a French Aircraft Carrier was not in the vicinity, or if there is a French Naval Base...
Thanks for your efforts.
PS
if it was found in a shark stop looking for the guy
