It is, unquestionably, a most unusual swimming class.

No backstroke or crawl, breaststroke or frog kick.

No splashing kids.

No water.

But these are the attractions that at last week's dryland session drew 16 adults who never learned to swim in their childhood or who are uncomfortable in water or who don't swim well enough to enjoy it.

In the past, many of them have signed up for traditional classes taught in a swimming pool, but those lessons haven't been of much help.

One student is a water-sports enthusiast. She canoes, bounces over river rapids in a raft and waterskis. Her goal? "I want to learn to swim without using a life jacket."

Another says she enjoys relaxing in a pool -- so long as she remains at the shallow end. "If I can't touch bottom, I get terrified. I like to say I have this respect for water."

A third wants to swim laps for exercise but only can do a few. "I think I'm breathing wrong. I can't relax."

That, says one more, is her problem. "I feel too tense to breathe well."

In our society, the inability to swim -- something most of us learn before we enter our teens -- can be a social disadvantage. It's our most popular leisure sport. Who wants to sit on shore when everybody else is romping in the surf? And there's the safety factor of knowing how to get out of deep water if an accident plunges you in.

"Adults who don't swim," says biologist Joe L. Griffin, who teaches the three-session Dryland Swim Course for Open University, "have special problems." Standard swimming classes, he says, "are designed for children -- even adult classes.But adults don't learn the way kids do."

Children, he suggests, learn through play, and "it is my observation adults do not play as long or as well as children." When it comes to trying to learn something that would have been easier in childhood, "they have trouble."

What happens, he says, is that "they wad up" by "trying too hard," constantly criticizing their performance and struggling for performance and struggling for perfection -- "trying for right. If you really get out there and try hard, you can screw yourself up."

Another block to learning is fearing that you will look foolish. "We all have this thing -- what if a kid laughed at us."

Instead of perfecting kicks and strokes, his students, he says, "learn how to learn" as they did as youngsters. The classes are a combination of confidence-building, body-awareness training and relaxation exercises aimed at getting the non-swimmers to feel comfortable once they do lower themselves into the water.

"You need to swim like you walk, so you can do it without thinking. We put together the bits and pieces and do what's easy."

ya great big pot-bellied man -- looking more like a lumpy walrus than the sleek dolphin you might imagine a swimming instructor to be -- Griffin quickly deflates doubts about learning to swim on the floor of a classroom at the Silver Spring United Presbyterian Church. He is dressed for this session not in bathing suit but in crumpled T-shirt, baggy Bermuda shorts and bare feet.

"If you're sort of sketpical but willing to do it, that's the way I want you to be. I'm very good at this. I really am. I think it works. People around me believe they can learn to swim."

ya research biologist (and chief of experimental neuropathology) at the Armed Forces Institute of Pathology at Walter Reed, he has been teaching these classes for about three years. Now 46, he learned to swim when he was "4 or 5" in a shallow creek in the Arkansas Ozarks. But, "I'm still trying to improve."

Much of the class's first two hours is spent in becoming aware of muscle movement in the back, shoulders and arms. These reaching and stretching exercises hint at standard swimming strokes. Students also practice breathing through the mouth and exhaling through the nose, another swimming basic.

Through practice, "it becomes automatic," he says. "Even in the water."

yin later sessions, he says, class members will stretch our on the floor -- imagining the surface to be both soft yet supporting, the way water is. "We play games in our minds about what it feels like.Imaginary exercises are very potent."

Rather than anticipate sinking in a deep pool, the students come to affirm, "I accept the support of the water." To learn to swim, he says, "takes a certain attitude." It involves "seeing water as a place to play rather than to struggle."

Griffin also provides an 11-page workbook for home and pool games directed at getting non-swimmers to relax. Included are tips for people who hate to put their head under water, among them touching your nose to water in a bowl of hanging your head under the shower and breathing though your mouth.

Keeping your face always above water, he says, can increase tension and makes moving through the water more tiring.

Throughout, Griffin preaches taking your time, which is how "children play and learn," seeking "improvement" and not "perfection."

ythe aim of his exercises: "Knowing [the swimming movements] at body level so securely that the head can relax and get out of the way" . . . when you enter the water.

yat an earlier class, Griffin says, two of his students, a husband and wife, were "hooked on sailng," but the wife couldn't swim. After the final session, she told him, "I now believe I can learn to swim." For some in his dryland classes, that is a big step.

The next step -- enrolling in Griffin's "wet" class.