Diving the Bermuda Deep

We had been planning this dive over our entire careers.

Our Mission: Descend more than 200 feet in open water, find the peak of a majestic volcanic seamount, then drop to below 450 feet to search for signs of ancient sea levels on what was once a small Atlantic atoll. Our dive would more than double the depth of previous underwater expeditions into the secretive Bermuda Deep.

Biologist Dr. Tom Iliffe and I scanned each other for bubbles and positioned our open-circuit bailout regulators within close reach. We nodded, with a last look at the support team on board the Pourquois Pas – “Why not?” – the name etched on the transom. I chuckled to myself. Iliffe and I glanced at each other, dumped the gas from our wings and rocketed downward, racing to ensure every possible moment would be spent gathering data and documenting our work. I filmed his descent from above, a tiny figure disappearing into the void.

Bermuda ranks high in the history of deep-sea exploration, yet technical scuba and rebreather diving is completely new here.

In 1934, Otis Barton and William Beebe made a record-breaking descent in Bermuda to more than 3,000 feet in their crude metal bathysphere. We would follow in the footsteps of a more recent, unmanned ROV, dispatched by Iliffe as part of a National Oceanographic and Atmospheric Administration mission to find Bermuda’s hidden underwater caves, to explore links between their prehistoric shorelines and the island’s unique cave ecology.

While famous for its caves, Bermuda does not permit recreational cave diving. This is based on efforts to protect these remarkable environments and the life within them. Bermuda caves are biodiversity hot spots for at least 25 critically endangered species, some of which are endemic to a single room in a single cave on the planet. As a result, only a few fortunate scientists and researchers are granted rare collecting and work permits allowing diving with the support of local guides. In this way, the underwater galleries and tunnels of Bermuda will be preserved as delicate time capsules of unique forms of cave-adapted life that might teach us about survival, evolution and the history of our planet. Our hope was to uncover caves or the evidence of former caves in the depths of the bank and seamounts, and perhaps reveal a migratory pathway for the unusual creatures still thriving on Bermuda today.

Iliffe and his team already had mapped the island’s walls and seamounts using side-scan sonar. Following the best leads, he deployed the ROV to create a video preview for targets we should dive. This unprecedented information gathering allowed us to focus on key features of interest to the mission’s scientists. Two years of advanced underwater imaging have brought us to the day’s objective.

The Dive Begins

Dangling his legs from the swim platform in the azure Caribbean water some 18 miles southwest of Bermuda, Iliffe quietly checked his equipment. An attentive safety diver assisted him as he prepped for what would be a challenging dive.

“Can you reach the clip for my bottom-left bailout bottle? I’m having trouble,” Iliffe said. “My sledgehammer seems to be in the way.”

In a calm but firm voice, dive-safety officer Brian Kakuk reminded us that this would be the last deep mission of the project.

I understood his inference: Often it’s the final dive of an expedition that seduces divers into unnecessary risk. Intent on completing all of a mission’s tasks, divers sometimes cut corners. They let the pressure lure them into dives that should have been shelved.

Kakuk was reminding us to keep cool and come home safely. If we had to abort this mission within a hair’s breadth of success to ensure our safety, we would.

Iliffe’s face is barely visible under the increasing load of equipment, now well over 250 pounds. He looks like a Transformer. I run through my own mental checklist. Rebreather: Checklist done. Four bailout tanks: Check. Camera on the transom: Check. Video lights, camera strobes, sample bag, measuring tape, reel, lift bags: All checked. Checked. And double-checked.

With my Sentinel rebreather, bailout tanks and video gear, gravity is not my friend. Slipping off the platform, it’s a relief to hang weightless, the bulk of my equipment suspended and neutral. Support diver Gil Nolan swims in a tight circle around me, giving me a final look, tugging on my gear, then nods approval to Kakuk. Alex Chequer from the Bermuda BioStation radios the Fisheries Department and the hospital, informing them that we are ready to descend. You could cut the tension with a knife, but it’s reassuring to know the entire island is on standby, supporting us with a safety team some 35 miles long.

The Challenger Bank

We reach the timeworn peak of the formidable Challenger Bank in less than three minutes.

A lonely lionfish hunkers in the clumping masses of coral where our hook jerks and bounces, dangling slightly, taut at its maximum reach. The orange surface marker is long out of sight, bobbing overhead on the waves marking our position. Moments like this make me acutely aware of my humanity, swimming awestruck in a place that has been out of reach until now.

Iliffe swiftly ties on his cave-diving reel and flies out over the precipitous drop. It seems like an eternity before he lands on a tiny crag at 460 feet, with the endless wall sloping infinitely downward and out of sight.

He locks off the dive reel, positions his mesh bags and tools and then intently goes to work. I train the camera on my usually reserved friend, preparing to document careful sampling. But Iliffe is like a Walmart shopper crashing through the door on Black Friday. We have only minutes at this depth, and he’s making the most of every breath. Hammer swinging and arms flailing, he grabs rock samples and delicate coral twigs. As though he were loading Noah’s Ark, he bags sets of animals, ensuring he has at least two of everything new or interesting.

I alternate between photographing his feats and the delicate wall, covered with fragile purple hard corals and crusting fiery sponges, flaming in bursts of color. Schools of curious jacks zip around us, while huge crab-eating permit reflect the sultry light back toward us. In this previously unexplored twilight zone, there is no shortage of extraordinary life.

Iliffe collected more than 50 species of plants and animals on those dives that today are yielding new discoveries for Bermuda, some previously unknown to biologists.

Geologists are studying our photographs and rock samples, trying to piece together the changes in sea level over time. Examining deep cave structures and wave-cut notches, they can now determine when sea level was at its lowest point.

The first glimpse into Bermuda’s netherworld suggests that exploration and discovery are still in the very early stages. Future work will focus on determining how the unique life in Bermuda first populated remote island caves.

Did cave-adapted animals migrate upward from deep ocean vents? Did they swim through tiny spaces within the matrix of rock? Or did they arrive in some other way?

We know more about outer space than we know about the pristine Bermuda, Argus and Challenger banks. Yet for those of us lucky enough to be working there, Bermuda Deep offers the chance to join the ranks of aquanauts on the edge of underwater discovery.

Tec Diving in Bermuda

Enrolling in a technical-diving class is one way to experience Bermuda’s rarely dived locations. Deeper dives are generally conducted on the sheer walls around the margin of the Bermuda Bank. Bermuda sits atop a large platform, so these dives are generally farther offshore than dives in recreational depths.

The ultimate tec dive in Bermuda is a visit to Argus Tower, some 35 miles southwest of the island. The peak of this volcanic seamount is reached at 192 feet; on it lie the remains of a submarine communications tower. With swarms of fish, including some large pelagics, this spot also attracts fishing boats seeking a prized catch.

Bermuda also has a very active scientific-diving community that is increasing its efforts on the front lines of the lionfish invasion. Researchers and technical divers have discovered a robust breeding population in the matrix of corals in the 200-foot range. Scientific and research organizations say they will appeal to qualified divers to aid in research and trapping.

Need to Know

You can dive year-round in Bermuda, but the most active season is May to October. Daily dive charters are available during the high season, but check ahead for scheduling. Water temperatures range between 65 degrees F in the winter and 82 in the summer, with visibility from 60 to 150 feet. Late-summer visibility is the lowest of the year.








For information on conservation efforts: oceansupport.org

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