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 six-person 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 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).
