Jill Heinerth: Deepest of the Deep

A life of an explorer is one filled with stories, and Jill Heinerth certainly has plenty to tell. With over 8,000 dives in her dive logs, it would be difficult to pick a favourite. But the most memorable journeys are the ones that tread the thin line between life and death.

Known as one of the world’s most accomplished cave divers, Jill Heinerth has dedicated 35 years of her life to underwater exploration. In 2001, accompanied by expert diver Paul Heinerth and cinematographer Wes Skiles, Heinerth led an expedition to Antarctica. Twenty-five years in the making, this National Geographic expedition was the first of its kind.

Convinced that exploring underwater iceberg caves would help scientists better understand climate change, Heinerth and her team dove into the B-15 Iceberg. A dive of this magnitude takes hours to complete, but the rapidly changing currents made it clear that B-15 had its own agenda.

On the surface, the iceberg calved, and a large chunk of ice sloughed off and closed the entry the team had used to enter the cave. After having to climb countercurrent, following fish to an alternate exit (with a ruptured glove), Heinerth surfaced to see the anxious faces of her teammates. “The cave tried to keep us today,” she blurted out.

Many of Heinerth’s cave-diving expeditions have been groundbreaking. “Some of those dives were as long as 22-hour missions, breaking records and going to places no one has ever seen,” she points out. Heinerth sees herself as a citizen scientist, extending the scope of science to hard-to-reach places and depths. One of these expeditions took her on a mission to the 300-feet-deep Wakulla Springs cave system in Florida, which not only broke world records for the longest deep-cave penetration dive but created the most intricate cave system map of its time.

For this project, she collaborated with Dr. Bill Stone, who created the mapping radar, which she had to manually operate underwater. Today this machine, named Sunfish, is a self-sufficient robot trained to “fetch” cave information, but its ultimate mission is to go to Jupiter’s moon, Europa, and explore the liquid oceans beneath its frozen surface.

“But today, this technology still follows in your footsteps, so to say.”

“It does,” Heinerth laughs.

Needless to say, an average oxygen tank is not nearly sufficient enough to sustain a diver on a multi-hour expedition into the Earth. The Wakulla Springs dive took 22 hours and was followed by 16 hours of decompression, a task impossible to complete with a standard oxygen tank. To make this dive possible, Heinerth worked with a team on advancements in rebreather technology, a recycling device that filters out carbon dioxide from used air and replenishes the oxygen supply on the go, allowing for longer dives. “It’s exactly the same thing that an astronaut wears to do a spacewalk,” she points out.

Rebreather technology is not without complexities and requires multiple people to “dress” a diver over a prolonged period of time. This kind of life support manipulation naturally comes with built-in risks.

“A small mistake or inattention can cause you to breathe a gas that could send you into a seizure or make you unconscious, so it’s very important to connect with deep commitment to safety protocols”.

Having come face-to-face with mortality more than once, Heinerth begins every dive with a check-in, evaluating possible risks, assessing her mental state, her team, and the environment, and thinking through every existential threat.

“An astronaut has Mission Control to call for help, but when I’m alone in a cave three kilometres under the ceiling of a rock, there is no Mission Control to call. I can’t afford to make mistakes or fail to monitor my gauges”.

“Have you had to cancel a dive last minute?”

“Absolutely,” she replied. “I think that’s one of the ultimate rules of survivors – knowing when to abort”.

Jill Heinerth is an official Explorer-in-Residence of The Royal Canadian Geographical Society, and their recent discovery exposed the final resting place of the Quest, a vessel of celebrated explorer Sir Ernest Shackleton, who died aboard the ship in 1922 en route to Antarctica. From shipwrecks to volcanic lakes, Heinerth has seen the Earth’s plumbing on every continent. She swam with polar bears and played catch with sea lions and as of late, she’s been diving under Ottawa’s Parliament Hill, exploring Canada’s longest underwater cave below the Ottawa River.

Between expeditions, Heinerth teaches at The Royal Canadian Geographical Society in Ottawa. As a young girl growing up in rural Canada, she found little encouragement to pursue a life of adventure, so her goal is to be the role model she didn’t have. “I talk to kids about exploration and discovery learning, employing their explorer’s mindset and nurturing their sense of curiosity,” she shared.

Many of Heinerth’s mentees have become National Geographic explorers and scientists in their own right. As a career explorer, Jill is also an active participant in Our World Underwater Scholarship, an organisation she’s been working with for over 30 years, fostering early interest in careers in science in children across the globe. Heinerth is a strong believer that people of any age and skill level can contribute to science by aligning themselves with local organisations and performing simple tasks, like reporting on water pollution or gathering data during leisurely time at sea.

Over the years, Heinerth has collected many accolades for her work as an explorer. “But you know, I guess if I had a secondary title, it would be storyteller,” she smiles. “I think that as an explorer, going to places that people have never been before, I have an opportunity to bring back stories, and so I’m communicating those in whatever format I can, through podcasts, articles and movies”.

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