Turk and pro kayaker Erik Boomer discovered this when, during the final week of their 1,485-mile circumnavigation of Ellesmere Island, a polar bear ripped a hole in their tent—while five other bears looked on.

The journey around the world’s tenth largest island, which took Turk and Boomer 104 days on skis, in kayaks, and on foot, was considered by polar experts to be the last great unattempted polar expedition, so daunting due to its remoteness and dangerous ice conditions. No one had attempted it before this summer.

For Turk, who pioneered big-wall climbs on Baffin Island and engaged in five Siberian expeditions to study shamanic culture, this was his “retirement party,” his last expedition. For the 26-year-old Boomer, who made a name for himself kayaking into the world’s wildest white water, this was the first of what he hopes will be many journeys to the Great North.

“I’m used to taking risks in short bursts, like in a single rapid or waterfall,” says Boomer. “This trip was so long, the risk so sustained and impossible to plan for. Jon is rare. He’s willing to do something where the outcome is unknown.”

In May, the duo began by dragging their 220-pound, 13.5-foot kayaks 800 miles across flat ice. As the ice broke up with the spring thaw, they were forced to jump over cracks and between unstable ice floes. By midsummer, they were able to paddle through slivers of open water.

Though the bears proved to be an ongoing danger—on one day they saw eleven, nine of which were aggressive—unfavorable winds were the greatest threat. Offshore winds pushed sea ice up against the sheer cliffs of Ellesmere’s rugged coast. Getting trapped between the two would mean certain death.

A text message Turk sent during the final leg of the trip summed it up best: “Bears scare us. We scare bears. The wind scares us. We don’t scare the wind.”