ANNAPOLIS HARBOR at sundown: Four watermen loitering dockside, guzzling Pabst Blue Ribbon until their bellies sag. A speedboat, Hot Chocolate, passes by. Out on deck smile three bikinied passengers, their legs sleek and long, their figures firm -- the total effect (one has to admit, even as the watermen start to bellow sweet nothings) quite dazzling.

"Hey," shouts one, breaking into a brown-toothed grin, "hot chocolate's my favorite brew." He winks and waves a tattooed arm, throwing in, for good measure, an intemperate suggestion. One of his comrades spits.

"Gawd-amighty," the second man yells, scoping Hot Chocolate's collegiate-looking pilot as the boat rumbles past, its engine like a wild animal drowning. "Wouldn't even make good cut-up crab bait in the salt brine."

A third waterman heaves a sigh. The fourth, beer in hand, staggers to port, leans overboard and simply heaves.

One watches enough of these scenes -- power-boaters sitting stolidly in their deck chairs with a diet drink; or sailors, that glint of arrogance in their eyes, standing ramrod-straight at the helm -- and a marvelous psychology of boating can emerge in all its glory.

The boat people of Annapolis, the city sometimes called "the sailing capital of the United States" (at other times, what with one for every thousand residents, "the gift shop capital"), are at it again this summer, providing perhaps the best case studies of boating culture to be found on either coast. The actual pastime of boating -- pitting commercial watermen against pleasure-seekers ("I wouldn't give you five cents for every sailboat from here to hell and back," says one old salt), stinkpotters against sailors and even, in an arcane subclass of a sailing controversy, the aficionados of J-24s against those who swear by Solings -- is but a minor aspect of the sociology.

In Annapolis, it is boating's periphery -- the dockside gawkers, the Huck Finns of sailing who trudge from boatyard to boatyard in quest of the perfect berth, the hydraulic winch fetishists, the catamaran brokers, and even those who want nothing to do with the water -- who drive the societal engine.

If this were not the case, one could find a parking space right now in downtown Annapolis and two empty boat slips in every marina. As any serious sailor knows, summer in Annapolis is the worst season, its climate rivaling a banana republic's, the weather swinging wildly from doldrum to deadly squall. Yet Annapolis is never more crowded than in summer, the bars and restaurants never more lively, the curio shops, tour boats and fudge factory never more patronized.

If boating conditions were the sole determinant of the strength of the boating society, Annapolis probably would bloom in the middle of March.

But Garrol Mace, director of the town's tourist office, has taken this summer to cursing his telephones. They ring too often. "Don't leave me like this," he pleads as a visitor bids him good-bye, his lines lighting up for the tenth time in as many minutes.

THE SHOCK OF RECOGNITION, the insight that explains so much, may occur even to the most casual observer. Take Holly Bazarnick, a 32-year-old former Annapolis resident who recently revisited her old haunts.

"Some sailors always seem to be talking about how long their boats are," she says.

Or how about Anne Arundel County Solicitor Richard Hillman, a native Annapolitan who avoids boats whenever he can? He claims to have made his own amazing discovery a few years ago, as a volunteer for the Annapolis Jaycees, shepherding cars into parking spaces during two successive boat shows.

"It's true, what they say about sailors and motor-boaters," Hillman reports. "During the sailboat show, the people were unfailingly polite and there was always very little trash left in the parking lot. They also seemed to be driving mostly Mercedes Benzes, Audis or whatever, small Volkswagens.

"Now, the motorboat crowd always seemed to be driving gigantic Lincolns, scattered trash everywhere, were generally a pain in the neck, and usually seemed to be smoking cigars."

Okay -- it's only one man's opinion, and that from a fellow who admits openly that he'd rather discuss jogging, of all things, than serious boating. (Sailors have their detractors, too, especially with the advent of nearly indestructible fiberglass boats, which require little maintenance compared to wooden vessels. "Some of those jerks bobbing up and down in Clorox bottles," says one veteran observer, "don't know port from starboard.")

Yet even without the precise methodology for which the social sciences are known, distinctions can be made, character types identified. For example: THE SOCIAL OUTCAST: "I've never sailed, myself," says Gerald W. Winegard, who was born in Annapolis, a city he represents in the Maryland House of Delegates, 35 years ago. "As a kid, I had a rowboat with five-horsepower motors, and I used to take it crabbing or fishing, but I never got into the sailboating crowd, never was taken in by the fetish.

"My God, I don't look at Annapolis as just a place to come visit quaint curio shops and bead shops and fudge factories. I look at Annapolis as my home."

For Winegrad, the two -- sailing and the quaint backdrop -- are inextricably linked, one the natural consequence of the other.

"When I was growing up," he says, "I remember being able to walk the entire shorelines. Now there's so many boat slips and condos over there, it's just impossible. Annapolis was once a sleepy little town; now, it's been transformed into a Georgetown. The next stage is Ocean City." As Winegrad says this, he shudders. "Actually, I'd say we're already beyond Georgetown."

Winegrad is strolling now down Main Street, his blue shoes noiseless against the sidewalk. They happen to be deck shoes, just the thing for a teak-trimmed schooner. "My wife picks all my clothes," he snaps.

Winegrad continues briskly down Main, pointing out -- like Marc Antony displaying Caesar's wounds -- the dress boutique that was once a country store, the upscale ice cream parlor that was once a five-and-dime, the preppy shirt shop that was once a neighborhood tavern, and the garish disco (this is the unkindest cut of all) that was once a homey Italian restaurant.

"It's nice to have a fudge factory, it's nice to have a bead shop, but we don't need three of each," Winegrad says. Later that night, he will not join the inveterate sailors at Marmaduke's Pub, where video-tapes of a recent regatta, not the mixed drinks, will rivet the patrons to the bar. Instead, Winegrad, kicking off his shoes, will settle into an Orioles game at home -- and light a cigar. THE SOCIAL LIONS: Skip Ronsaville, a local catamaran dealer, puts down his binoculars and smirks.

"I don't see how you could possibly grow up here and not sail," Ronasville says, his spare frame perched on the edge of a canvas chair. "I mean, you'd have to be retarded."

A 40-year-old native who returned to Annapolis after eight years as an Air Force helo pilot and Exxon engineer, Ronsaville sits outside his dealership, a million-dollar concern on the top deck of the Yachthaven boat supply center in Eastport, a section of the city separated from downtown by Spa Creek.

From this vantage point, on a third-floor terrace, Ronsaville has an unobstructed -- and with binoculars, magnified -- view of the Harborplace condominiums, six $300,000 units with private boat slips and a vista of the Annapolis skyline. Ronsaville likes to look at the condos, since he owns one. (actually two, he says later, as he shows off the nearly built condo; one here and one across the river, plus, of course, a house.)

"Sailing," he breathes, "is a sensual sport, as far as I'm concerned. So many people use it as just another battle ground, an outlet for stress. I don't see how they reduce stress by simply looking for another valley to fight in."

Ronsaville shakes his head at such unmellowness. "See, it can be simple or complex, it can stretch your mind or turn off your head. It has motion and speed-potential, and the feeling of pure acceleration."

Sensual, yes, but precise. So says Dr. Stuart Walker, a local pediatrician who has competed in the Olympics and helped found Annapolis' Severn Sailing Association in 1952.

An excerpt from one of Walker's six books on sailing, Wind and Strategy, page 59:

"The Dry Adiabatic Lapse Rate is 1 degree C. per 100 meters; when the air is saturated (at levels above condensation) the Adiabatic Lapse Rate is approximately one-half as great, or 0.5 degrees C, per 100 meters. The average lapse rate of surrounding air is 0.66 degrees C. per 100 meters. Lifting, therefore, usually causes lifted air to cool more rapidly than the surrounding air and is self-limiting."

Just over five feet of well-connected sinew, Walker has a shock of white hair and devastating hazel eyes ("They're so piercing," says a woman acquaintance. "So beautiful.") HUCK FINN: He hitched-hiked into town two weeks before, the worse for a bout with the New England Seaboard; Newport and Gloucester, where he found the people icy; then Salem, where (he says) he offered himself as racing crew and they decided he was a witch. Now Bert Bozarth, 25, a sometime literature major from New York's Wechester County ("Melville's my main man," he says), nurses a beer at Marmaduke's Pub in Eastport. Here are environs he finds more congenial.

"I just walked into the Annapolis Boatyard and asked the first guy I saw where the cemetery was so I could crash for the night," Bozarth says. "He said, 'Hell, you can crash on my living room floor,' I said it sounded good to me."

Since then, Bozarth, who grew up with boats near the Hudson River, has been commissioning vessels in the yard, even crewing in a race or two.

"There's a lot I don't know," he says, steadily turning his glass. "What I'd really like to do is sail across the ocean, maybe take a movie camera and put together a film. You get involved in something and suddenly you think of a thousand possibilities." THE STINKPOTTER: His bright yellow slacks and white bucks belying his wistful mood, the bald Navy captain gazes at the 40 feet of motor-cruiser before him at the Eastport dock.

She is, no argument, a handsome vessel: fine woodwork, gleaming paint, and, after four other boats, he had finally broken down and named her Half Moon. That, of course, was a bit of vanity, since Half Moon was also the aircraft tender he commanded in the Second World War.

It would be a shame to have to lose her.

"He wants to take her south in the fall, but who knows," says the captain's wife, a handsome woman in her sixties. "I don't know, Jack."

"I'm 69 years old," the captain, a big man with large hands, says with a grin, "but I don't feel old. Really, I feel like a young man. But I've got $100,000 in her, and I have to decide by September whether I sell her.

"Never liked to sail," he goes on. "When I was a plebe over there at the Naval Academy," he indicates the huge gray dormitory across the river, "this was in 1928, they sent us out in sailboats and I got, I got --"

"Becalmed," murmurs the captain's wife.

"That's it," he agrees, nodding vigorously, "becalmed. They were supposed to tow me in, but they didn't, and I had to stay out there until midnight. Ended up having to do 15 hours' extra duty for being missing," he chuckles.

"Never liked to sail since. Anyway, when you grow older, you need a little power behind you."

The captain's wife, a petite woman, kisses him on the top of his bald head. She does this easily, as the captain is sitting in a wheel chair.