seconds to return. In that gap, the ship
has moved forward, and has pitched
and rolled atop the surface of the sea.
Bongiovanni also had to account for
readings of sound speed at each dive
site, as it is affected by variations in tem-
perature, salinity, and depth.
The purchase and installation of the
EM-124 cost more than the ship itself,
but its software was full of bugs. Each
day, Bongiovanni oscillated between
awe and frustration as she rebooted it,
adjusted parameters, cleaned up noisy
data, and sent e-mails to Kongsberg,
the maker, to request software patches.
The expedition wasn’t merely the first
to dive the South Sandwich Trench but
the first to map it as well.
Buckle positioned the ship over the
dive site. A Triton mechanic named
Steve Chappell was assigned the role
of “swimmer,” meaning that he would
balance atop the Limiting Factor as it
was lowered into the water, and dis-
connect the towline before it went
down. He wore a dry suit; polar waters
can rapidly induce involuntary gasping
and vertigo, and even talented swim-
mers can drown within two minutes.
For a moment, he lay on a submarine
bucking in the middle of the South-
ern Ocean, fumbling with wet ropes,
fingers numb. Then a Zodiac picked
him up and took him back to the Pres-
sure Drop, where he warmed his hands
by an exhaust vent. Vescovo started the
pumps, and the Limiting Factor began
its descent.
Dive protocols required that Ves-
covo check in with the surface every
fifteen minutes and announce his depth
and heading and the status of his
life-support system. But, after forty-five
hundred metres, the communications
system failed. The ship could still re-
ceive Vescovo’s transmissions, but Ves-
covo couldn’t hear the replies.
Aphids and krill drifted past the
viewports. It is customary to abort a
dive thirty minutes after losing com-
munications, but Vescovo knew that he
might never have another chance to
reach the bottom of the Southern
Ocean, so he kept going. He liked the
sensation of being truly alone. Some-
times, on the surface, he spoke of human
nature as if it were something he had
studied from the outside. Another hour
passed before he reached the deepest
point: seven thousand four hundred andthirty-three metres. The point had never
been measured or named. He decided
to call it the Factorian Deep.T
hat night, Alan Jamieson, the chief
scientist, stood on the aft deck,
waiting for biological samples to reach
the surface. “Most marine science is
gritty as fuck,” he told me. “It’s not just
‘Look at the beautiful animal,’ or ‘Look
at the mysteries of the deep.’ It’s all the
weird vessels we end up on, the work
of hauling things in and out of the
water.” Jamieson, a gruff, forty-two-
year-old marine biologist, who grew
up in the Scottish Lowlands, is a pio-
neer in the construction and use of
hadal landers—large, unmanned con-
traptions with baited traps and cam-
eras, dropped over the side of a ship.
In the past two decades, he has carried
out hundreds of lander deployments
in the world’s deep spots, and found
evidence of fish and critters where none
were thought to be. Now, as snow blew
sideways in the darkness and the wind,
he threw a grappling hook over the
South Sandwich Trench and caught a
lander thrashing in the waves.
There were five landers on board.
Three were equipped with advanced
tracking and communications gear, to
lend navigational support to the sub
underwater. The two others were Jamie-
son’s—built with an aluminum frame,
disposable weights, and a sapphire win-
dow for the camera, to withstand the
pressure at depth. Before each dive, he
tied a dead mackerel to a metal bar in
front of the camera, to draw in hungry
hadal fauna. Now, as he studied the
footage, he discovered four new spe-
cies of fish. Amphipods scuttled across
the featureless sediment on the seafloor,
and devoured the mackerel down to its
bones. They are ancient, insect-like
scavengers, whose bodies accommo-
date the water—floating organs in a
waxy exoskeleton. Their cells have
adapted to cope with high pressure, and
“they’ve got this ridiculously stretchy
gut, so they can eat about three times
their body size,” Jamieson explained.
Marine biologists classify creatures in
the hadal zone as “extremophiles.”
The following night, one of Jamie-
son’s landers was lost. “Usually, things
come back up where you put them, but
it just didn’t,” Buckle said. “We worked