Doug Allan

The brothers largely remain estranged until Pack's death a decade or so later, in 1958.

Meanwhile, not long after the war, the French Navy creates what it calls the Underwater Research Group to teach sailors to dive.

Tallier, as the most senior officer, is the commander, and Cousteau is his deputy.

Largely left to their own devices, the group is tasked with clearing French harbors of mines and sunken wrecks.

Yet there is still time for filmmaking and for satisfying their growing curiosity about the underwater world.

The men egg each other on, attempting to break new records, despite the known risks.

In 1947, attempting a new depth record, the team loses one of their own.

A diver called Maurice Farg reaches 385 feet, but loses consciousness underwater.

It is the Aqualung's first fatality.

Yet despite the tragedy, demand for Cousteau's invention continues to grow.

Before long, the Aqualung is being sold not only across Europe, but also in the United States and Canada.

With publicity building, Cousteau hires his father as a business agent.

When Cousteau Sr.

helps set up a screening of his son's short films, a magazine editor makes inquiries about the Frenchman who can breathe underwater.

The resulting seven-page feature in Life magazine, featuring the diver's dramatic photos of sharks, reaches more than 10 million readers.

A week later, Cousteau accepts an offer from Universal Studios of $11,000 for his first four documentaries.

But for that, he needs a vessel of his own, and soon the perfect solution is found.

The wooden-hulled Calypso began its life during the Second World War as a British minesweeper.

The Cousteaus remortgage their house to help renovate the Calypso, and Simone sells her jewelry to raise more funds.

Cousteau refits the vessel for exploration, adding a bulbous bow with eight viewing windows for filming underwater.