Bore Tides: Against the Current

Bore Tides: Against the Current

via The Atlantic: http://www.theatlantic.com/infocus/2013/08/bore-tides-against-the-current/100582/

a few places on Earth, local geography and tidal conditions align to cause a phenomenon called a tidal bore: An incoming high tide collides with the outgoing tide in a narrow channel, generating a turbulent wave front