ON A CHILL, MISERABLE FEBRUARY night, under a cold rain that blew in bullets across the Outer Banks of North Carolina, 190 men and women crawled up a Sahara-high sand dune on their bellies. The men were bare-chested. The women wore only pajama-thin linen suits. Both the men and the women growled and groaned, pulling their bodies up the steep, coarse sand, using only arms and elbows, two fistfuls at a time.

The frightening wind-twisted sound of their ordeal was heightened in the darkness, like the tormented wail of long-drowned pirates. Yet at least one among the crawlers wished things were worse.

"I was hoping it would snow. That's the whole point of having this camp in February," said Steve Mahan, a 31-year-old Virginia Beach lawyer and black belt in karate. Mahan and the others clawing their way up the damp sand paid $47 each to attend this karate camp in Nags Head. Internists, child psychologists, certified public accountants, they are students of karate as taught by Hiroshi Hamada, a 24th-generation samurai and "Martial Artist in Residence" at Old Dominion University, a man with a complex biography who once raced dragsters at a North Carolina speedway. He is 43 but has the body of a high school wrestler.

Hamada stood halfway up the dune, stern-visaged. He barked commands at the dark, writhing shapes of his students. It was a moment that would bring a smile to any Green Beret.

"Y OU MUST FORGET yourself . . . bring out the vast strength . . . break the barriers," Hamada told his students. "When your small egos are for the first time crushed . . . crawl over your dead body . . . control all your trembling fear."

As weekends at the beach go, the Greater Japanese Martial Arts Virtue Society's training camp was short on leisure. For nearly 28 straight hours, these men and women from half a dozen mid-Atlantic states who follow Hamada were subjected to an ordeal that included much more than clambering up frozen sand dunes: There were periodic plunges in the 36-degree Atlantic surf and hours of exhausting exercises in martial artistry that bore little resemblance to the celluloid bone crushing of Chuck Norris, Bruce Lee or the Karate Kid.

"We teach discipline, courtesy, manners," said Hamada, who has taught martial arts to more than 20,000 students since arriving in the United States 22 years ago. Only 200 of those students endured long enough to achieve black belt status. The rest were done in by their inability or unwillingness to submit to karate's regimen. "The goal is not winning competitions, participating in tournaments or gaining fame. We teach discipline, courtesy, manners . . . a total way of life."

That way of life, grounded in Zen philosophy and eastern traditions of unarmed combat a few thousand years old, might seem impossibly alien to a western life style. But the college students and older representatives of yuppiedom at this camp found much that was familiar -- the discipline of Marine boot camp, the zeal of an EST seminar, aerobics with a lethal kick.

CAMP BEGINS IN A second-floor bar of the Armada Resort Hotel, a seven-story box on the vacation strip just down the beach from The Ghost Ship Restaurant and Teeny Man's Lounge. Two dozen black belts are seated before an elevated platform where Hamada, who is addressed as "Shihan," or teacher, delivers instructions. The black belts will be both students and teachers at the camp, responsible for the progress and physical safety of the lesser ranked students, the white, yellow, green, blue and brown belts.

"You may go into shock," warns Hamada calmly, making eye contact with each of his students. "You must know when to retreat."

The black belts respond with a loud, guttural "osu," a Japanese word that roughly translates as "courage" and is used in much the way an Army private uses "Yes, sir." The salute of a karate-doh student is a quick, submissive bow. It is performed frequently.

Instructions over, Hamada lowers his voice to a deep growl and extends a samurai sword used by a 17th-century ancestor to commit seppuku, or ritual suicide. "He took every intestine out of his body while he still lived and placed it in front of him," says Hamada, slowly unsheathing the sword and twisting the blade to reflect the artificial light. "We all need such courage. You must decide when, where, to what purpose."

"Osu."

THE FIRST ORDEAL is an ocean plunge. After an hour of intense, kinetic exercise, the students jog from a carpeted conference room to the beach behind the hotel.

Spread according to rank across 60 yards of frigid shore, dressed only in thin linen exercise suits called gis, they perform katas, choreographed blocks, kicks and punches against imaginary foes. Their shouts, even on the endless windy beach, are loud enough to scare the seagulls.

Slowly the students advance into the breaking surf. Hamada faces them, submerged to his thighs, apparently oblivious of the three-foot waves that crash against him. From the beach, the tableau resembles a scene from a Kurosawa film. From the opposite vantage point, with the resort hotel and a Kentucky Fried Chicken as backdrop, it could as easily be a Monty Python spoof, "Samurai at the Shore."

That contrast, of ancient, eastern asceticism practiced in the glare of western consumerism, is personified by Hamada. As a 9-year-old in postwar Japan, he was sent to live for five years in a Zen temple. He came to the United States in 1964 to attend college in North Carolina on a Methodist Church scholarship. He has hitchhiked across America, worked as a cowboy in Oklahoma and sung with a folk group for spare change.

He now lives with his wife and two children in Virginia Beach and teaches Zen, Japanese and sociology at Old Dominion University in Norfolk. He also teaches karate-doh at both Old Dominion and the College of William and Mary. He is a thoroughly modern samurai, a writer of poetry with a complex sense of humor that is not obvious at the karate camps he conducts each year. Some of the students who have followed Hamada for years say he has mellowed: No longer are students led on hour-long runs over gravel or kicked hard enough to send them flying into gymnasium bleachers as punishment for improper form.

"At the first camp there were 100 students. No more than 15 or 20 ever came back," says 35-year-old Bill Stocky, who has attended every camp but one since the first in 1973. A former William and Mary football player, Stocky now works as a librarian for the U.S. Court of Appeals in Washington. His reason for studying the martial arts is starkly simple: "I grew up in New York City."

John Ballou, a 32-year-old computer analyst, was motivated by a sucker punch he caught after nabbing a shoplifter while working at a department store in college. Lynn Strickland, a graduate student in geology at George Washington University, took karate for a quick gym credit. That was 10 years ago.

It is not difficult to understand the attraction of karate in a violent and secular world. It is harder to understand why so many middle-class students persevere in such a rigorous, demanding discipline. There are easier ways to stay in shape. And spiritual enlightenment is promised by other teachers at a much lower cost in loyalty and submission.

The question is not easily answered by Hamada's students. After nearly 15 hours of punching the sky and kicking the surf, Fred Adkinson, a 35-year-old real estate investor, drips water on the hotel carpet and admits confusion. "It's not fun. I hurt all over."

Stocky says there are rewards in accrued goals and shared pain: "I've got a small family at home. I've got a bigger family here." Mahan compares himself to a painter who improves with every brushstroke: "It's an art form. It just happens to be a martial art."

The question of motivation, says Hamada, is like a Zen riddle: It cannot be answered until there is no longer any reason to ask it. But stand close enough to feel the energy that radiates from 190 people tapping into their own electric current, look into eyes that reflect a calm most people achieve only in moments just before sleep and you might recognize something close to the human core, something as sweet and scary as the midnight sound of a God-blessed choir.

"There is something as powerful as the wind, the ocean and the earth," says Hamada as he stands below the crest of the dune, facing his students. "Your compassion to each other. Your human love."

The students converge for a group embrace and warrior cheer. Back in formation, they jog across the sand to the parking lot where their BMWs and Mazda RX7s will carry them to the hotel for another 12 hours of testing. Behind them they leave a dune higher than a Washington apartment building. It is scored with the vertical lines of their crawl.