A man kayaking in San Francisco Bay Saturday morning spotted the shark you see in the video above, which swam up to his kayak and then under it before swimming off.
He was not able to identify the species, but it was possibly a spiny dogfish? Dogfish sharks only grow to between two and four feet long.
There are, as we know, even bigger sharks in the Bay at times, like the great white caught on video preying on a seal near Alcatraz last fall. Great white sightings have become more common here, especially in this El Nino year due to warmer waters, and a cluster of about 20 great whites was spotted off of Ocean Beach just two weeks after that Alcatraz sighting.