Did a 20-foot long predator take a bite out of a great white shark—half its size—off the coast of Australia? Experts reviewing a gruesome photo of the great white believe that its assailant must have been 20 feet long based upon its bite marks. The wounded shark is still alive; its attacker is still at large. "I've heard about the big one lurking. Every surfer is always cautious over here,” a surfer said.