Usually when I post a kayaking video it is of someone running utterly spectacular rapids or dropping off an insanely high waterfall. But this clip is completely different. It takes us to Umfin Island off the coast of Ireland, where we find intrepid paddler Iain Miller making his way toward shore, than paddling through a natural canal, until he reaches a sea cave at the heart of the island. Undaunted, the kayaker presses on, into the cave and under the island itself, proceeding with a headlamp to light the way. The passage is more than 300 meters in length, making it quite the undertaking to explore. Check out this amazing little expedition below.