This is the scary moment a kayaker in Austria got trapped in between and under rocks in whitewater rapids.

In the video, filmed in October 2013, German kayaker Adrian Mattern, then 18, is paddling with a friend on a difficult Grade V run when he gets submerged underwater.

"One small mistake lead to this very dangerous and close-call situation where I got trapped in between rocks underwater. Luckily the gap underwater was big enough to crawl my way through just to reappear. After another very dangerous rapid, I got luckily flushed down without major injuries.

In the end, Mattern makes a swim to safety "alive but in shock."

He writes: "Big lessons were learned that day. The river is boss, always."

Cheating death whilst extreme whitewater kayaking in Austria. Watch a kayaker get trapped in between and under rocks in raging whitewater getting lucky and making it out alive. POV!

In October 2013, German kayaker Adrian Mattern was paddling with one friend on the Oetztaler Ache in Austria. This class V run is very dangerous and considered as the "Eiger Nordwand of kayaking" . One small mistake leads to this very dangerous and close call situation where he gets trapped in between rocks underwater. Sheer luck was that the gap underwater was big enough for the then-18-year-old, to crawl his way through just to reappear after another very dangerous rapid he got luckily flushed down without major injuries. At last, a swim with the last bit of energy left in him, Adrian made it to shore and was alive but in shock. Big lessons were learned that day. The river is boss, always.

Shot on GoPro 3 black in 720p 120p