http://www.nbcbayarea.com/news/local-be ... 17914.html
At the link above you'll find the news story and a video of the kayaker describing what happened with the great white shark. He was near Pescadero, California (about 50 miles south of San Francisco) and the shark actually grabbed the kayak from the bottom and lifted it. When lifted, the kayaker fell out. The best part in the video is when he says he looked straight down into the sharks mouth and saw all those teeth!
Earlier this month (august 2), another kayaker's boat was attacked by a great white shark. The kayaker was in the Santa Barbara channel. It wasn't as exciting as the one at the link above.