Vee Wertime, 57, a bowling businesswoman, rock collector and occasional stunt flyer from Chambersburg, Pa., glanced casually around at the trees, smiling serenely. Richard Rodriquez, 20, sometime Harvard student, fidgeted in his seat slapping the sides of the steel car. "Let's go." he shouted.Charles Jacques, 38-year-old attorney from Pittsburgh, clutched his Nikon, but appeared less confident. Then the cars on Busch Gardens' "Loch Ness Monster," the country's tallest and steepest roller coaster, began to move.

It was the ultimate moment of "Coaster Con-I," the first convention ever of roller coaster enthusiasts.

Ten minutes later, having experienced four slow, soundless climbs to a point 130 feet above a lake, four descents of mind, body and soul 114.2 feet at 55 degrees and at a speed that accelerates from 12 to 60 m.p.h. (though it feels like the rush of the Concorde) in the first minute of the ride, there was Wertime adjusting her glasses, smiling joyfully. "This is why they call me Roller Coaster Granny,'" she called out. Her 31-year-old daughter, slightly paled, got off. Jacques still didn't look comfortable, but he didn't budge from his back seat, the acknowledged high.

As for Rodriguez, obsession had contorted his round baby face. He's a record-setter - last week 110 hours on the "Swamp Fox" at Myrtle Beach, S.C., before that he broke his own record of 103 hours, 55 minutes on the world's most famous coaster, "The Cyclone" at Coney Island. He's a hero in this crazy world.

And as he rode the "Loch Ness," a cub, not a lion for these fans, and all he said, very calmy, was "I'm not getting off."

"Coaster Con-I" brought together 40 hard-core coaster buffs, who study, photograph, ride - and walk - what they call (and few would dispute) America's most thrilling ride, the roller coaster. And who wouldn't love something that Lindbergh adored and Walt Disney despaired of?

For three days they discussed coaster history, coaster lore, coaster designers, coaster extinction, coaster revival and, most importantly, coaster rides. In a hotel exhibition hall, they examined each other's models, slides and homemade movies. In their other lives the coaster crazies are apparently sensible people: a 29-year-old admissions officer, a 62-year-old salesman at Marshall Field, a 42-year-old music teacher, and a 22-year-old Pentagon clerk-typist, plus several college students.

"The Loch Ness Monster," $5 million worth of steel, which debuted last week and has had 55,000 riders, bears little resemblance to a 15-century Russian ice slide, its ancestor. By the 1920s the United States had 1,000 roller coasters. The highest ever built in that era, and the count varies between 120 and 138 feet, was "Blue Streak" in Poughkeepsie, N.Y.

All-time favorites include the "Cyclone" at Crystal Beach Amusement Park, Ontario, which had a nurse at the unloading platform, Coney Island's "Cyclone", the "Thunderbolt," at Kennywood, outside Pittsburgh, and the "Bobs" at the old Riverview Park, Chicago. But few, according to both historians and connoisseurs, could beat the nameless grande dame at Palisades Park, N.J., for its thrilling curves and majestic view.

About four years ago, the number of American coaster had dwindled to one historian's count of 200, enthusiasts argue that only 90 of those had any guts. The coaster attrition was caused by wars, inflation and the death of old-fashioned carnivals and seaside resorts.

Now, with the tremendous boom in family-style theme amusement parks, like Busch Gardens, roller coaster are coming back. This year alone, said Paul Greenwald, 32, a guide at Niagara Falls, ski instructor, and one of the convention organizers, "about a dozen are being built. It's the busiest year since the 1920s. There are twin coasters, two all-wood coasters, several corkscrews and shuttle loops, a twin shuttle loop. The new parks have to build them because the parents expect to see a coaster and the kids want that same thrill?

What is the thrill?

Generally, on any coaster, the illusion of danger. Few other experiences cause the blood to rush, the body to jerk helplessly, with the stomach ending up in the throat, and the voice screaming - all at the same time.

And, on the dwindling number of wooden coaster which most of the enthusiasts prefer, the rating of the cars fuelled thoughts of impending doom. The whole contraption, including chains still used to go up the first hill, sounded like goodbye time.

On the "Loch Ness" the riders beat the sides of the cars, chanting "Go! Go!" all the way up, down and around. The screams seemed rehearsed until the "Monster's Lair," an 18-second ride through a tunnel, where the tracks were tilted and the air suffocating. That was exciting.

"Well, I've been on about 50. "Thunderbolt" at Kennywood is my favorite.Have you seen it? It's built in natural valley and has beautiful curves," said Betsy Abrahms, 21, a wisp of a college student from White Plains, N.Y. "It's all pretty neat. Some of my friends think I'm sick. I was solo flying at 16."

Because she was quicker than anybody else, Abrahms got a front seat. "The front gives you a sense of the angle," she explained. On the sidelines was her mother who noted that "Betsy's mad because they strap you in. She like to stand up in those things. But really," and she paused, ready to confide, "she's a brillant student. She takes nuclear calculus, physics, all those things. She already has a job lined up at Cape Canaveral. I don't want her to stand up in that damn thing." When her daughter had gone around for the 10th or 12 time, her mother said, "I once did a study on the pyschology of the high-board diver. Most of them had come from restrictive homes. There was nothing wrong with Betsy's home."

When George Berbert, 62, and Clarence Hintze, 55, saw "Cinerama" 25 years ago, they decided to make a movie about changing scenes in Chicago. Again and again they found themselves at the now-demolished Riverview Park.

"Then it had seven coasters, maybe eight. But I think the 'Jack Rabbit' had just closed. Now when I see our film, I get a lump in my throat," said Berbert.

For 32 years he has worked at Marshall Field and is also vice president of the Wagner Society of America. His friend, Hintze, is working on a discography of Buddy Rich. Hintze stopped filming the screaming riders on the "Loch Ness" for a moment, and said "What I like is the beauty. The thoughts of what they can do with steel and wood to scare the hell out of you, I want a coaster with something inside that's a beast, a monster." But he goes on them all, "even the kiddies 'Scooby-Doo' at King's Dominion."

Looking through his camera, Hintze muttered, "Now why don't they time those two loops so we could have cars in both of them at the same time?" For a few moments he stared at his digital watch and the interlocking loops, then said "Only 15 seconds apart. That would have been beautiful."

Standing in front of the darkened hotel room, Joseph T. Barna explained why "Earthquake," the coaster at San Diego's now-closed Belmont Park, should be saved.

He walked the length of the track, measured everything, slept by it for three days, and took some beautiful pictures of the coaster alive, and, well, dead. "Look at the axle, 20 feet wide. The cars have beautiful craftsmanship," said Barna, 29, his voice low and sad. The coaster, built in 1925, is the onlyone in the country with Historic Landmark status out it is threatened by development. "Now I'll pass around this petition because we have got to save this one, and the 'Cyclone' at Coney Island. The wood ones are great Americana, we can't let them go." Applause and "Hear! Hear!" from around the room.

Barna grew up in coaster-barren Vermont and is now graduate student in theater technology at Yale. No one calls him crazy.

And that's because "my friend who makes my T-shirts is into subways," said Barna, pausing for effect and a closer inspection of his blue cotton T that advertised the convention. "He hates Paris but goes to ride the subways. He's very sympathetic." Last summer during the one month he had off from studies, Barna spent $200 on an Amerpass bus ticket, visited a dozen coasters, and spent much more money on film.

"What coaster riding has is intensity. Your attention is focused on one thing, like meditation. But this is more dramatic," said Barna. "People pay thousand of dollars for primalscream therapy. Why not do this? It cleanse you."

Richard Murch has gone from coward to leader. He grew up a few subway stops from Rockaway Beach and Coney Island but he wouldn't ride the coaster.Then about six years ago, during a beach party at Rockaway, he tried. "I was thrilled by the drops, the speed changes, the coolness. I didn't know how I had missed this," said Murch.

Now he's a widely known name in the coaster revival movement. And the wearer of a red work shirt from the crew at Coney Islands "Cyclone." Last year Murch was one of the enthusiasts invited by Universal Pictures for a promotional coaster marathon at King's Dominion for the movie "Roller Coaster."

"We all got together and agreed we had to organize formally. This is it." said Murch, who lives at home with his parents in Astoria, Queens, studies architecture at the City College of New York and works part-time in a bank. "My parents are just beginning to see the seriousness of this and are pleased I am doing a book.

If the decade were the '50's, and some people are acting like it is, Richard Rodriguez could be the new Sal Mineo. His picture, he says, is already in the discos in his Brooklyn neighborhood of Bay Ridge, smack in "Saturday Night Fever" country.

His record-breaking coaster-ride marathons are now charity. In the fall he will appear on Jerry Lewis' telethon. "The contest takes a lot of physical concentration," said Rodriguez No. 20, a short, boxy man. "I do 180 pushups every night, jog six miles a day. When I started out, I used to ride the playground swings for hours just to get used to the constant motion.

"But what has really helped is listening to music, the Rolling Stones, above all, 'Jumpin' Jack Flash' is my favorite. When you are all alone at night on top of the coaster, you need something soothing. So I have music stored in my head and I sing."