O
N 28 APRIL, after three years of intensive prepara-
tion, Victor Vescovo fi nally reached what’s now
the deepest-known part of the planet: 10,928m
under the ocean in the Pacifi c. Nestled inside a
purpose-built deep-submergence vehicle (DSV)
called Limiting Factor, he dived to the bottom of the deepest ocean
trench, reaching 16m further than anyone before. The previous
record for a solo dive was 10,908m, set by fi lmmaker and explorer
James Cameron in the Deepsea Challenger in 2012.
Victor’s record-breaking dive took him deeper than
Mt Everest is high, to a cold, lightless, high-pressure place as
inaccessible as outer space. It was the fourth successful leg of his
Five Deeps Expedition, which was designed to send a human to
the very bottom of each of the world’s fi ve oceans: the Puerto
Rico Trench in the Atlantic, South Sandwich Trench in the
Southern Ocean, Java Trench in the Indian Ocean, Challenger
Deep in the Pacifi c and Molloy Deep in the Arctic. The latter
was the last left to reach at the time of going to press. A fi ve-
part documentary series fi lmed by Atlantic Productions is due
to be shown on the Discovery Channel at the end of this year.T
HE DECISION TO embark on the Five Deeps Expedition
was made by Victor in 2015 while undertaking The
Explorers Grand Slam – climbing the highest moun-
tain on each of the seven continents and skiing to both the
north and south poles. After exploring Earth’s highest peaks
it seemed natural he should seek its lowest depths. But he’d
been mulling over the concept well before that and already
knew there was a huge problem: he’d need a submersible craftcapable of repeated dives to some of Earth’s most inhospitable
places and such a thing didn’t yet exist.
And so Victor partnered with Triton Submarines, based in
Florida, to design, build and test the next generation of deep ocean
research and adventure vehicles. The result was a submersible
that resembled a white-bread sandwich. It was offi cially dubbed
Tr iton 36,0 0 0/2 (for 36,000-foot capable, with two persons) or
FOD Triton (Full Ocean Depth). Victor, however, christened it
Limiting Factor after the name of a spaceship in a book authored
by the late science fi ction writer Iain M. Banks.
Limiting Factor is a revolutionary craft but to explain why, it’s
necessary to recap some deep sea history and marine physics.Launching the Limiting Factor submersible into the wild and
frigid Southern Ocean from the stern of DSSV Pressure Drop was
like a fi nely choreographed ballet for humans and heavy machinery.is an adventurer and three-time
AG Society awardee. He was
expedition doctor on the Southern
Ocean and Mariana Trench legs of
the Five Deeps Expedition and was
part of James Cameron’s Deepsea
Challenger team.Dr Glenn Singleman
98 Australian GeographicPHOTO CREDITS, PREVIOUS PAGE: RICHARD VARCOE; THIS PAGE, TOP: GLEN SINGLEMAN; BOTTOM: RICHARD VARCOE;OPPOSITE PAGE, TOP TO BOTTOM: GLENN SINGLEMAN; DR ALAN JAMIESON; RICHARD VARCOE