Immodestly I claim some credit for the change in attitude, for while the Jaws phenomenon was blamed for distorting the public’s view of sharks and causing sporadic outbreaks of macho mayhem, it also generated a fascination with and, over time, an affection for sharks that had not existed before. These days I receive more than a thousand letters a year from youngsters who were not alive when Jaws appeared, and all of them, without exception, want to know more about sharks in general and great whites in particular.

Great white sharks are among the true apex predators in the ocean. The largest predatory fish in the world, they have few natural enemies. And so, in balanced nature, there are not very many great whites, and the number grows or shrinks depending on availability of food. They breed late in life and pup relatively few. Again, nobody knows exactly how many, but seven or eight seems to be a safe average. The youngsters appear alive, four or five feet long, weighing 50 or 60 pounds, fully armed and ready to rumble. Still, many don’t survive the first year because other sharks, including great whites, will eat them.

Of all the infuriating unknowns about great white sharks, none is more controversial than size. How big can they grow to be? Fishermen from Nova Scotia to South Australia, from Cape Town to Cape Cod claim to have encountered 25-footers, 30-footers, even 36-footers. (Usually the proof offered is that the beast was “bigger than the boat.”) There have been reports of a 23-footer in the waters off Malta and a 21-foot, 7,000-pounder off Cuba, but none has held up under scrutiny. The largest generally accepted catch—made by lasso, of all things—was a shark 19.5 feet long. The largest great white shark ever caught on rod and reel weighed 2,664 pounds.

According to British biologist Ian Fergusson, chairman of the Shark Trust, no great white shark longer than 19.5 feet has ever been validated, and in an e-mail widely circulated last spring, he expressed irritation at “this stubborn reluctance by some elements of the media to accept the facts and even more of a reluctance to accept that a 16-foot, 4,500-pound white shark is BIG, very BIG, and should need no further exaggeration to impress even the most discerning of viewers when seen up close.”

I can attest that underwater, cruising toward you out of the gloom with the serene confidence of the invincible, a 12-foot great white looks like a locomotive with malice in mind.

When the belly of the dead shark was open, Barry Bruce beamed. “Look at that liver,” he exclaimed. “That’s a 500-pound liver.” The liver is an immense energy-storage facility, and I liked Rodney’s clear and simple description of how it governs the shark’s feeding habits. “If a shark has eaten a whole seal or sea lion,” he said, “it might not have to eat for a month. But the smell of chum or bait or blood in the water will stimulate the feeding impulse, and it may decide to top off its tank of energy.”