http://www.newsweek.com/close-encounter-great-white-shark-caught-video-two-fishermen-australia-1004295

A great white shark startled a couple of fisherman off the coast of Australia on Sunday after the creature appeared to chase the men in their kayaks. 

At one point, one of the men, Ken Gerke, had to slap the water with his paddle to scare off the shark.  A shaky video shows a dark fin quickly cutting through the water toward his boat.