Jacques-Yves Cousteau wears a Blancpain Fifty Fathoms

Cousteau and the crew of the Calypso shot twenty five kilometers of film over two years, in the Mediterranean, the Persian Gulf, the Red Sea, and the Indian Ocean, and cut it down to two and a half for The Silent World (1956), co-directed with a young Louis Malle. It won the Palme d'Or at Cannes, the only documentary to manage that until Fahrenheit 9/11 almost half a century later, and then the Academy Award for best documentary. Parts of it are hard to watch now. The crew dynamites a reef to catalog the fish, with Cousteau narrating that the method is illegal but acceptable in the name of science, and when an injured baby whale draws sharks, the crew kills the sharks.

The record of what the team wore is unusually good, because Blancpain itself tells it. The Fifty Fathoms had been built three years earlier to a specification drawn up by two French Navy combat swimmers, Bob Maloubier and Claude Riffaud, who shopped their requirements to several watchmakers before a former Navy officer at Spirotechnique introduced them to Blancpain's Jean-Jacques Fiechter, an avid diver in the world's first diving club who had once nearly run out of air underwater and designed accordingly: a crown sealed with double gaskets, a screwed-down two piece caseback, a bezel that locked until pressed. The first watches were delivered in 1953 in 42 millimeter steel cases, and Blancpain's own account says Cousteau selected Fifty Fathoms watches for the diving team whose dives the film records.

Whose wrist carried which watch is where the experts part ways. Several of the standard histories put the Fifty Fathoms on Cousteau himself during the dive sequences. Others, looking hard at the frames, read the captain's own watch as probably an early Rolex Submariner reference 6205, and place the first series Fifty Fathoms on Andre Laban, his chief diver and engineer. The film's images do not settle it; in the production stills the watch on Cousteau's arm is a dark shape on a strap in one scene and a glint of steel bracelet in another. No one disputes that the team carried Fifty Fathoms, and the histories agree the watch proved a hit with divers around the world after The Silent World.