Kayaking around icebergs and glaciers is a fun way to spend time outdoors in Alaska, but it can also be an incredibly dangerous experience — Andrew Hooper and Josh Bastyr have learned their lesson.

The pair went kayaking around remote Spencer Glacier a few days ago for what they thought would be a tranquil paddle, but turned out to be “the biggest adrenaline rush of [their] lives.”

Not aware that they were too close to the glacier, Hooper and Bastyr did not leave the area when they heard cracking, but instead went closer to inspect the source of the noise. They witnessed Spencer Glacier’s dramatic calving a mere few feet from their boats.

The video from their experience is impressive, but also scary — the two could have died from the projection of ice and the tsunami that followed the collapse. Hooper explained on Instagram, “We are so grateful to be alive and in total awe of the power of nature.”