The shortfin mako is an incomparable model of shark. The specifications are: armor-tough hide covering thick sinuous body; tail to drive it at 40 knots or launch it like a Trident missile; fully automatic cruise control; muscle- wrapped jaw equipped with 52 ranks of teeth; and the beast is good to eat.

It can be yours, for a limited time only, while the supply lasts: Mid-Atlantic makos run from June to mid-July. But there's one important catch. After you've dropped a fair piece of change on a charter boat, braved blustery weather on open sea and waited long hours for a nibble, there might be no catch at all.

"I explain to all my shark parties, especially my new shark parties, that shark fishing is not a lot of action all day," said Pete Floyd, a charter captain working out of Lewes, Delaware, a three-hour drive from Washington. "Some days, there's no action. That's when you think, 'Boy, I can't believe this is happening to me.' "

Things threatened to turn just so the other day, as a party of mako-hunters set out with Floyd from Lewes. No one could have predicted a great adventure in misery: biting winds, six-foot swells, water sloshing in torrents through the cabin, widespread wooziness -- and no makos.

By day's end, luckily, no one would have had to, and the catch exceeded even the most unreasonable expectations.

For a few stalwarts -- Michael Kramer, Christopher Buckley and Peter Teeley -- it was a return engagement; on a jaunt last fall, as they'd bragged at length to the others, they'd hooked ten dusky and brown sharks, and a couple of bluefish as well.

There had been a big buildup for this second expedition. "Cap'n Pete hauls 'em into his boat barehanded and fights 'em to the death on deck," was one of Teeley's milder claims. The banter, and the smiles, faded into a Dramamine daze as the morning wore away.

"This is all rather pointless, isn't it?" Buckley said grimly, heading for a bunk. Kramer, an experienced sailor, was pale and spent after his first bout with seasickness.

"Let's go home," Teeley said at last, glancing worriedly at Kramer, who was lying atop the bait chest in the stern of Chargeo I, a 34- foot fiberglass sportfishing boat. It was hardly mid-morning, but skipper and mate had started reeling in hooks and pulling up the chum bucket. Kramer opened his eyes and cried, "No! No. We're not turning back because of me. I'll be fine." There was steel in his voice. "Let's stay. Let's stay till we get a shark."

The hooks were rebaited with mackerel, the chum bucket resubmerged.

Along with the great white, tiger, hammerhead and other ocean-going marvels, the mako's one of the larger sharks loosely labeled "man-eater" -- though none is known to have eaten a man, and only about a dozen have taken nips at swimmers in the last hundred years of shark-attack reports.

The mako does eat meat, however, some 15 times its own weight in a year -- mostly swordfish, bluefish and squid. Males can grow to more than 300 pounds; females can reach 1,200. Less is known about the shark's other habits. It bears live young, as many as a dozen in a litter, but no one has seen it mate. It travels long distances, sometimes thousands of miles from point to point, but no one knows if that's migration or wandering. It may live as long as 30 years, but there's no foolproof way of telling.

To meet one, meanwhile, you'll have to ship out. "They're just too wild -- even the smaller ones -- to keep in an aquarium," said biologist Jack Casey of the National Marine Fisheries Service. "I know of many aquariums that would love to have a mako; I know of some that have tried, and the shark hasn't lasted too long. They have to be swimming constantly, and because of their high metabolic rate, they're very susceptible to stress. You try to transport them, and they're still fighting and go right into shock."

The writer Zane Grey, who hunted makos in the 1930s, waxed lyrical about them. "A premier sporting fish," hh raved. "As game, as beautiful, as ferocious, as enduring . . ." The impetuous Ernest Heminway took a less sporting attitude; his favorite shark-fishing tackle was the tommygun.

"Hemingway used to say that it was the only shark he knew of that would more or less play dead after you landed it, then try to bite you if you came anywhere near,"said Casey. "He actually caught a world's record mako in 1936: 789 pounds, off the coast of Bimini." The record was beaten long ago.

The mako only lately has become a popular East Coast game fish. Last year sport fishermen landed some 14,000 from Cape Hatteras to Cape Cod, said Casey, who runs a shark- tagging program from the fishery service laboratory at Narragansett, Rhode Island. Such hunting, he said, is all to the good, acquainting folks with makos as a valuable natural resource.

Maybe a scarce one, too, as it seemed the other day.

Rough seas all morning had kept Floyd's party from the prime fishing grounds, a spot about 40 miles southeast of Lewes known as Five Fathom Light. Half an hour after Mike Kramer made his stand against surrender, the wind had begun to drop and the sea was starting to "lay down." Another half-hour and the skipper revved up the engines and made for Five Fathom Light.

Shortly before noon Floyd cut the engines and his mate, a college kid named Chet Rohrbach, baited the lines, 80-pound test on two heavy rods, and re-dunked the chum, an oily, smelly puree of ground-up bunker fish. Then they waited, the chum slick drifting across the blue-gray water.

Within minutes, the skipper and mate were pointing. A hundred feet to starboard a shark surfaced, chomped on a bait and sped away scot-free. Rohrbach rebaited. All was quiet again.

The shark hunters, cold and wet, were scattered about the boat: Buckley half-asleep in a fighting chair, Kramer still atop the bait chest, Teeley on the flying bridge, and others lounging in the cabin.

It was just past one o'clock when one of the rods shuddered; the reel began to spin. For a frozen moment the hunters merely watched. The reel whirred as the line spun out, some 200 yards gone in a few seconds. The cabin laggards came dashing on deck.

"Look. Look!" Pete Floyd shouted. "It's jumping!" Only Floyd and Rohrbach saw it; they jumped, too.

"You take it, Mike," Buckley said to Kramer, now alert and on his feet.

"No, you better," Kramer demurred.

Rohrbach helped Buckley into a vest-like harness as he grabbed the rod from its holder and planted himself in a fighting chair. The skipper scurried up to the bridge. The rod bent like a bow.

"How big is it?" Buckley asked frantically, trying to work the reel.

"Don't give him any slack," Floyd called from the bridge.

"How big is it?" Buckley said between grunts.

"It's big," Rohrbach said.

Things happened quickly. The fish let Buckley reel it in, then took off in a burst of speed, let him reel again, and took off once more. It dived and lunged, and once lashed the surface into spray about a hundred yards astern. Teeley and Rohrbach shouted advice. Floyd kept the stern to the fish as Buckley fought for 40 minutes to get it to the boat, where the monster thrashed and thrashed.

The skipper scampered down from the bridge to help with gaffing and roping. Leaning overboard, he shot it twice in the brain with a stainless-steel revolver. It took five pairs of hands ten minutes to haul the thing aboard, where all took care to stay away from the faintly twitching jaws.

It was a large male mako. "Biggest I've ever seen," the skipper said, wiping his brow.

The shark measured 93 1/2 inches from snout to tail and weighed in at 307 1/2 pounds, 15 1/2 pounds more than the winner of this year's Bay Shore Mako Tournament, the granddaddy of East Coast shark competitions.

At the scales in Lewes, a crush of fifty people, something of a welcoming party, crowded hting and round. Floyd -- "You've done it again, Pete," someone called -- straddled the shark and smilingly posed for pictures. Buckley, still in harness, was getting edged to the back of the gathering. He craned his neck from a distance, peering between heads and over shoulders.

"Congratulations, Pete," someone shouted. After a while the shark was butchered; Buckley and Teeley decided to give most of the meat away. Locals and tourists alike swarmed about and stripped the mako clean. A Lewes policeman came back for seconds and tossed it into his cruiser. An elderly lady, grinning, marched up and down the dock, her outstretched palms cradling stacks of mako steaks. When there was no more, the crowd thinned to a few old-timers still marveling at the haul.

The flurry of handshakes done, Floyd ambled up to Buckley, who was standing off by himself, looking somewhat contemplative and still in harness.

"Uh, I'm sorry, buddy," the skipper said, "but I'm gonna have to relieve you of that."