Nineteen Sixty

In the captain's mess after dinner, someone had pinned a black-and-white photograph to the wall. It showed two men in cloth caps standing on the deck of an older, blockier vessel. Behind them was a strange machine, more bathtub than submarine, with a small spherical compartment hung underneath an enormous tank.

The two men were Jacques Piccard and Don Walsh. The date written under the photograph in faded marker was January 23, 1960. The vessel was the bathyscaphe Trieste, and on that day they had become the first human beings to reach the bottom of the Challenger Deep.

Polly perched on the back of a chair and studied the picture. The Trieste was a wonderful machine, and a terrifying one. Its pressure hull was a steel ball just under two metres across with walls thirteen centimetres thick. The float chamber above it, holding more than a hundred thousand litres of gasoline (which is lighter than seawater and difficult to compress), gave the whole craft its buoyancy. When they wanted to descend, they vented some of the gasoline. When they wanted to come back up, they dropped iron pellets carried as ballast.

That was the entire system. No engine, no electronic depth control. Just the chemistry of gasoline versus seawater, and an act of faith.

The descent took four hours and forty-eight minutes. At about nine thousand metres, one of the outer Plexiglas viewports cracked. Piccard and Walsh felt the whole craft jolt and heard a sharp report. They considered turning back. They did not.

At 10,911 metres, the Trieste settled into a pale clay seabed. Walsh later reported seeing a creature he described as a flatfish, perhaps a foot long, drifting at that depth, a claim still debated by biologists. They stayed at the bottom for twenty minutes. Then they began the slow rise back to the world.

Fifty-two years passed before the next person reached the same depth. James Cameron, the film director, made the dive alone in 2012, in a craft he had helped design. After Cameron came Victor Vescovo, who in 2019 began making the dive repeatedly, eventually carrying others down with him.

Polly looked at the photograph for a long time. There was something about the gap, fifty-two years between the first dive and the second, that struck her. The deepest place on Earth, visited once, and then left alone for half a century. As if humans had checked it off a list and gone home.

From the galley next door came the soft clink of someone washing dishes, and the low murmur of a radio. The mess hall lamp was warm. The photograph hung quietly on its nail, three men looking out from a winter morning sixty-six years ago, when the deepest place on Earth was about to be visited for the first and, for a long time, only time.