Diving deep: the centuries-long quest to explore the deepest ocean
Schemes to dive to the bottom of the sea have a surprisingly long history — but a book shows how science has rarely been the motivation
Dawn Wright and Victor Vescovo after their journey to the ocean’s deepest point in 2022.Credit: Nick Verola, Verola Media, Caladan Oceanic, and EYOS Expeditions
The Frontier Below: The Past, Present and Future of Our Quest to Go Deeper Underwater Jeff Maynard William Collins (2023)
On 12 July 2022, oceanographer Dawn Wright climbed into the submersible Limiting Factor, alongside pilot and explorer Victor Vescovo, and descended nearly 11 kilometres to the bottom of Challenger Deep in the western Pacific Ocean. She became the 23rd human to reach the ocean’s deepest known point — and the first Black person.
Like climbing Mount Everest, reaching the oceans’ greatest depths remains an adventure and a privilege beyond the reach of most. Many more people have scaled Earth’s heights, but in The Frontier Below, Jeff Maynard recounts the push to plumb the depths. It is a brisk tour through the history of diving and submersibles, heavy on engineering and light on science.
That’s fitting, because the endeavour was hardly ever about science. Pearls from the depths tempted the first free divers to develop their extraordinary lungs and swimming abilities. Goods from wrecked vessels convinced helmeted divers to venture into murky estuarine waters. Military interests drove attempts to breathe under water as far back as antiquity.
Some research did happen. In the 1620s, Dutch inventor Cornelis Drebbel, who is thought to have built the first submarine, might have isolated oxygen to aid breathing underwater. In the 1660s, Robert Hooke at the London Royal Society hauled inverted buckets of air beneath the waves to explore how air and water pressure changed with depth. Hooke’s employer, Robert Boyle, demonstrated that compressing air makes its container less buoyant.
Everybody, it seems, was coming up with ideas about how people could spend more time under water. In the 1690s, English astronomer Edmond Halley devised a system in which barrels of air were lowered to a diving bell so swimmers could work on salvage operations; he recounts that he and four others tested it to some 18 metres down. By the early eighteenth century, an unknown artisan in Finland had stitched together the world’s oldest preserved diving suit, supplied by an air hose and made of leather with seams sealed with pitch. It probably leaked terribly.
Going deeper into the oceans meant battling the physics of air and water to work out how to maintain breathable supplies of air, and how to return without the dreaded ‘bends’, a condition in which nitrogen bubbles form in the blood.
Maynard, a writer who has been involved in historical diving societies, goes into great detail about the development of early diving techniques. Tanks of compressed air appeared on the scene in 1860, thanks to the French mining engineer Benoît Rouquayrol. In 1878, English sailor Henry Fleuss invented a way to trickle oxygen through a breathing mask and circulate the exhalations over yarn soaked in potash to remove excess carbon dioxide. This opened the way for the modern scuba, the ‘self-contained underwater breathing apparatus’.
The greatest depths
Maynard’s narrative quickens as he shifts to the race to build deep-sea vessels. The cast of characters is wide and wild, beginning with US engineer Otis Barton. In the late 1920s, he designed and funded the building of a ‘bathysphere’, a metal sphere that could be lowered into the depths on a cable from a ship. Barton collaborated and ultimately fought with William Beebe, a naturalist with the New York Zoological Park who grabbed the spotlight for their joint deep-sea dives.
In 1930, they reached 245 metres, a record. Four years later, they made it down to around 900 metres. Beebe wrote evocatively of these descents: “Until I am actually enclosed within some futuristic rocket and start on a voyage into interstellar space, I shall never experience such a feeling of complete isolation from the surface of the planet Earth”.
The bathyscaphe Trieste carried Jacques Piccard and Don Walsh almost 11,000 metres down into Challenger Deep in 1960.Credit: Bettmann/Getty
The race broke wide open in the late 1940s, with the invention of the bathyscaphe — essentially a bathysphere with better buoyancy control — by the Swiss physicist Auguste Piccard, who had made his name ascending to great heights in balloons. Piccard and his son Jacques partnered with Italian engineers and funders to build several bathyscaphes. In 1953, they reached 3.1 kilometres deep. A year later, a rival French team, led by Georges Houot and Pierre Willm, plunged to 4 kilometres.
After this, the big dive to the Challenger Deep was the one great prize left to grasp. The US Navy purchased the Piccards’ vessel, Trieste, and put its lieutenant Don Walsh on board. In 1960 Walsh and Jacques Piccard descended to the deepest spot in the oceans.
It was a time of renewed interest in the deepest seas. US leaders had suggested deep-ocean trenches could be an excellent place to dump nuclear waste, arguing that the material would stay contained and there was no life down there to worry about, anyway. On reaching the bottom, Piccard reported seeing a fish, flat and with eyes; some have speculated that this was a lie, intended to deter any plans for nuclear dumping.
The Frontier Below misses chances to discuss the science of the depths. The first major oceanographic survey, conducted by the British Royal Navy ship HMS Challenger — after which the Challenger Deep is named — in the 1870s is dispensed with in just over a page. The discredited ‘aquatic ape’ theory that humans evolved in the water makes an unfortunate, if brief, appearance. Maynard dispenses quickly with modern developments in oceanographic exploration, such as underwater piloted vessels including the US Navy’s Alvin, operated by the Woods Hole Oceanographic Institution in Massachusetts, which since commissioning in 1964 has explored the biology and geology of the deep sea over thousands of dives. The remotely operated, tethered vessels that are increasingly used for purposes including deep-sea mining also barely figure.
These are omissions: ultimately, it is humanity’s impact on the deep ocean that will shape our future. The quest to go deeper should be motivated by improving understanding of how the deep ocean works and what is to be found there, the better to protect it. When Vescovo first descended to Challenger Deep, in 2019, he found not a flat fish, but a plastic bag.
Nature 616, 653-654 (2023)
doi: https://doi.org/10.1038/d41586-023-01372-8
This story originally appeared on: Nature - Author:Witze, Alexandra
