Transcript for Kayaker attacked by great white shark

Back now with the stunning shark attack caught on camera. The great white knocking a man out of his kayak in the open ocean. Here's ABC's aerial reshef. I've seen a shark attack, I'm filming it! Reporter: Tonight a diver surviving an encounter with a shark. See that kayak? Reporter: The shark circling this kayaker moments after knocking him into the water 100 yards off the coast of Monterey, California. Watch as the shark chomps on the boat like a chew toy, then turns towards the swimmer. See the fin? Swimming towards the guy now. Reporter: On lookers capturing the encounter on camera. Call somebody, Karen. Oh, my gosh. Reporter: The kayaker, experienced diver waved to boats nearby, used a gps tracker and called for help. They better hurry. Reporter: A family in a sail boat seeing him in distress and keeping him calm until the coast guard arrived. Just make yourself as small as possible. And keep your eyes on that shark. Reporter: This incident coming amid recent warnings that more sharks are lurking closto the California coast. Authorities so concerned they used helicopters and loud speakers alerting swimmers to danger. Exit the water in a calm manner. Reporter: The kayaker says he reminded himself don't splash, keep your eyes on the shark and swim away.

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