Every surfer knows the importance of catching the perfect wave - but what if that wave went on for miles against the current, sometimes with entire trees caught up as debris in its wake?

The Pororoca is a tidal bore, traveling up to 500 miles upstream as the direction of the Amazon’s current is reversed by high ocean tide in the Atlantic.

Best of Earth Science: http://bit.ly/EarthLabOriginals
Best of BBC Earth: http://bit.ly/TheBestOfBBCEarthVideos

This is a channel from BBC Studios who help fund new BBC programmes. Service information and feedback: http://bbcworldwide.com/vod-feedback-...