Βeneath the Sea Ice

A dive into sub-zero Arctic waters uncovers long-kept secrets

- By Meaghan Brackenbury

Jill Heinerth pulls on a neoprene balaclava and adjusts her thick rubber gloves. Wearing a dry suit, red helmet and 20-kilogram tank filled with compressed air, the underwater explorer stands at the floe edge in Tallurutiup Imanga (formerly known as Lancaster Sound), Nunavut, the eastern entrance of the Northwest Passage in Canada.

Heinerth is joined by her colleague Mario Cyr, two Inuit guides and a sixperson camera crew. It’s June 2018, and Heinerth and Cyr are going to dive beneath the sea ice and film what they see.

“The floe edge is like a moving buffet,” says Heinerth. “Every day, as it breaks away, it releases ice and nutrients into the ocean. In the summer, polar bears and narwhals, belugas and eider ducks come to feed.”

It’s the perfect spot to dive, but getting there wasn’t easy. During spring, the floe edge can move miles per day as it breaks up. The team—on snowmobiles pulling sleds called qamutiit packed with scuba gear— slogged through slushy top water and around growing leads (long cracks in the ice) until they found it, roughly 50 miles from shore outside the hamlet of Ikpiarjuk (Arctic Bay).

Heinerth and Cyr—hailing from Ontario and Quebec, respectively—do one last check of their gear. They are each attached to a rope held at the other end by a guide. The rope helps the divers find their way back out through the ice. Through a tug from the guide, it also warns them if a polar bear is nearby. Tightening their flippers and popping regulators into their mouths, they jump into the frigid water and sink beneath the surface.