To Change Our Human Perspective, We Need to See What Lurks In the Deep Ocean

Astronauts who have gazed on Earth from space sometimes report revelations about the fragile beauty and interconnectedness of our planet, which has become popularly known as the “overview” effect. But for travelers who yearn to travel in the other direction, preferring undersea submersibles to spacecraft, an “underview” awaits that reveals entrancing creatures, clues about our existence, and secrets that we’ve hidden from ourselves across the centuries.

Susan Casey, who is the author of several books about the seas, finally took the plunge into this mysterious realm in her new work The Underworld: Journeys to the Depths of the Ocean, which was published on Tuesday. The Underworld is a love letter to the deep sea and a clarion call about the pressures humans are placing on its hidden ecosystems. It’s also a spirited adventure story that follows Casey on a quest to become one of the few people on Earth to witness this vibrant world with her own eyes. 

“The descent into the underworld is going to test you, but it is also where the treasures are,” Casey said in a call with Motherboard. “Our culture seems to think of things in this very linear way: We belong up here, we're looking upwards; we like to progress and move forward; we like to expand. But the deep ocean requires us to go inward into darkness.”

“It’s an alien world to Homo sapiens, but at the same time, the Earth’s biosphere is 98 percent ocean and 95 percent deep ocean,” she continued. “This whole journey inward is essential if we're ever to know, with any experiential understanding, where we live.”

Deep sea exploration might normally seem like a niche topic, but it recently attracted huge public interest in the wake of the implosion of the OceanGate Titan submersible in June. The disaster bolstered the view that people simply shouldn’t explore the seas (see also: orca uprisings and surfboard-swiping otters).

Casey had considered diving to the wreckage of the Titanic with OceanGate during the reporting of the book, but passed after industry experts warned her about the company’s lax attitude toward safety. She ultimately hitched two rides to the deep sea on “classed” vessels, meaning submersibles properly certified for their target depths. OceanGate’s submersibles, in contrast, were not classed for its deep sea trips. 

Casey’s first dive was on Neptune, a submersible operated by the company OceanX, which brought her a half-mile under the waves near the Pacific Island of Tonga. Her second voyage descended a whopping three miles under the Hawaiian seas, onboard a well-established Triton submersible. Experiencing these surreal domains further persuaded Casey of the profound value offered by human deep sea exploration.

“I do hope that people get a chance to get into manned submersibles if they want because it really is life-changing and alters your perspective on just about everything,” she said. “Before this Titan tragedy, there had never been a fatal accident for 50 years [in deep sea diving] because we know exactly what you're going to encounter at whatever depth the submersibles are going to go.”

“It’s the same way that on an airplane, if something goes wrong, there are ten backup systems,” she noted. “That's why you certify a submersible and you go through all the rigorous testing, and OceanGate did none of that. It was such an outlier.”

The desire to see what lurks far below the waves, and to document and preserve it, is a persistent one. In fact, OceanGate traded on this desire when it advertised its Titanic expeditions, frequently portraying dives as scientific missions aimed at understanding the changing ecology around the wreck. 

Casey hopes that deep sea exploration will become more affordable and accessible—without sacrificing safety—so people can experience this habitat with their own eyes, or even just experience it vicariously through submersible footage. A better understanding of the depths could help conserve them from a host of human threats, including deep-sea mining, bottom trawling, plastic pollution, and climate change. 

The pressures we are placing on these enigmatic ecosystems have remained largely out-of-sight and out-of-mind, but the consequences of anthropomorphic damage to the deep sea will come back to bite us eventually. 

This habitat potentially served as the cradle of life on Earth, and may contain clues about the existence of life on other dark ocean worlds, such as Jupiter’s moon Europa. It is also a critical player in the geological cycles that have allowed life on our planet to survive and thrive. The underworld is filled with wonders, and terrors, and warnings about our way of life. We ignore it at our own peril.

“The ocean has nothing but time,” Casey concluded. “If we really mess with it enough, we're going to get a pretty nasty backhand at some point. I mean, why would we do that? We live on a planet that's 98 percent ocean and you're going to try to fuck with it? So, it's up to us.”