The massive great white, believed to be 18 feet long, was spotted Wednesday.
One surfer snapped a picture as the shark partially breached the ocean surface. The image he captured only shows half of the animal's giant dorsal fin.
Professional surfer Sean Fowler also caught a glimpse of the shark about 200 yards from the beach.
"Right when he came towards me and told me about it, that's when I saw it breach again and saw the biggest fin I think I've ever seen," said Fowler.
Great white sightings near Imperial Beach are extremely rare. Swimmers were urged to stay out of the water for a couple of days.