Conversation so far:
What is the organization GERS?
Cousteau and Tailliez showed Épaves to Admiral Lemonnier, who gave them the responsibility of setting up the Groupement de Recherches Sous-marines. Later it became the GERS.
What did the GERS do?
The GERS small team undertook the exploration of the Roman wreck of Mahdia.
Are there any other interesting aspects about the Jacques Cousteau article besides the GERS small team undertaking the exploration of the Roman wreck of Mahdia?
In 1947, Chief Petty Officer Maurice Fargues became the first diver to die using an aqualung.
What is an aqualung device?
Aqua-Lung was the first open-circuit, self-contained underwater breathing apparatus (or SCUBA) to reach worldwide popularity and commercial success.
How did Maurice Fargues die while working with GERS?
Maurice Fargues became the first diver to die using an aqualung, while attempting a new depth record with the GERS near Toulon.
Were there any other incidents with GERS, besides the death of Maurice Fargues?
Cousteau and the Élie Monnier took part in the rescue of Professor Jacques Piccard's bathyscaphe.

Question: Who was Elie Monnier?
Self-contained rewrite: Who was Elie Monnier in the context of Jacques Cousteau's work?