It 's `` a juvenile great white shark about 10 to 12 feet long , '' expert David Shiffman says . `` The tail is flat , '' like a dolphin -- not a shark , expert Jeff Kurr says . Discovery Channel shark expert Jeff Kurr calls it a great white shark , but shark expert David Shiffman believes it was a dolphin . David Shiffman snapped the photo of her son and friends playing in the surf . Great white sharks are no danger to southern Manhattan Beach swimmers , expert says .
It 's `` a juvenile great white shark about 10 to 12 feet long , '' expert David Shiffman says . `` The tail is flat , '' like a dolphin -- not a shark , expert Jeff Kurr says . David Shiffman snapped the photo of her son and friends playing in the surf . Great white sharks are no danger to southern Manhattan Beach swimmers , expert says .