Great white sharks are notoriously bloodthirsty, and this one was caught on camera circling a fishing boat in the aftermath of its kill of a sea lion.
Mike McGill's Instagram post showed a great white shark swimming toward the boat about 14 miles from San Diego's Mission Bay.
In the summer, great white sharks populate all of California's coastal waters.
Juvenile great white sharks have been seen frequently in the waters off San Diego in recent years.
White shark pups, being particularly defenceless, stick to the shallows.
An approaching great white shark can be seen in the video, prompting several passengers to exclaim, "Oh my god!"