David and I exchanged a glance. The shark’s reaction struck us both as quite similar to the phenomenon scientists call tonic immobility. We had heard that other sharks, smaller sharks, can be made to pause in a kind of suspended animation when turned over on their backs. Had Andre’s hand somehow had the same effect, perhaps by interrupting the flow of sensory signals that activate the shark’s brain? Or perhaps Andre actually overstimulated the shark’s sensory organs. No one knows. Maybe the shark simply grew confused by being unable to reach something with its jaws that it sensed was nearby.

What I do know is that neither David nor I had ever heard of, let alone seen, such behavior between a human being and the most feared of all the creatures in the sea.

By now, however, we were growing used to the unusual, for in nearly every encounter we had had with great whites over the past six months, from the stormy Southern Ocean off Australia to here on the southeastern tip of the African continent, the magnificent animals seemed intent on defying conventional wisdom and confounding the experts.

The more we learned, the more we realized how little is really known about great whites. Despite vast leaps of knowledge since Jaws was published in 1974, no one—not scientists, fishermen, or divers—yet knows for certain such basic things as how big they can be (how long, how broad, how heavy), how many years they can live, how many of them exist, when and where they mate, how many young they can carry, where they spend their time, and what, specifically, impels one great white shark to attack, kill, and consume a human being and another to bite and spit out the same hapless sort of victim.

I became convinced, too, that considering the knowledge accumulated about great whites in the past 25 years, I couldn’t possibly write Jaws today … not in good conscience anyway.

Back then, it was generally accepted that great whites were anthropophagous (they ate people) by choice. Now we know that almost every attack on a human is an accident: The shark mistakes the human for its normal prey.

Back then, we thought that once a great white scented blood, it launched a feeding frenzy that inevitably led to death. Now we know that nearly three-quarters of all bite victims survive, perhaps because the shark recognizes that it has made a mistake and doesn’t return for a second bite.

Back then, we believed that great whites attacked boats. Now we know that their sensory systems detect movement, sound, and electrical fields (such as those caused by metal and motors) in water, and when they approach a boat, they’re merely coming to investigate. (Granted, investigation by a 3,000-pound animal can wreak havoc.)

Finally, back then, it was OK to demonize an animal, especially a shark, because man had done so since the beginning of time, and, besides, sharks appeared to be infinite in number.

No longer. Today we know that these most wonderful of natural-born killers, these exquisite creatures of evolution, are not only not villains, they are victims in danger of—if not extinction quite yet—serious, perhaps even catastrophic, decline. Much of the evidence is anecdotal: Fishermen and naturalists are seeing fewer great whites, and in most places those they are seeing are younger and smaller.