Conversation so far:
When was the first film Jacques Cousteau made?
The two neighbors took the first ex-aequo prize of the Congress of Documentary Film in 1943.
What was special about this film that it won an award?
1943, for the first French underwater film: Par dix-huit metres de fond (18 meters deep), made without breathing apparatus the previous year in the Embiez islands.
Did they make another film after that?
In 1943, they made the film Epaves.
What made this film special?
they used two of the very first Aqua-Lung prototypes.

Question: Who created the prototypes?
Self-contained rewrite: Who created the very first Aqua-Lung prototypes?