"Okay, who's afraid to go through this one?" By midafternoon, Mike May, an instructor for Washington Whitewater, had sized up his group of would-be kayakers. Ahead lay Stubblefield Falls, its faint white peaks licking the horizon.

We were clustered around some rocks in the middle of the Potomac -- 10 students. Mike and two volunteer assistants, Bob and Gail. Sleek 14-foot kayaks angled off awkwardly from our waists. It was as if we had been given wings but had not yet learned how to fly. We had left the nest that morning at Old Angler's Inn.

Dressed like trick-or-treaters from Mars -- in various wetsuits, old wool sweaters, baggy shorts, orange lifejackets, purple tights, yellow helmets and apron-like neoprene spray shirts -- we carried the flatbottomed polyethylene boats down to the muddy riverbank. Among us were a college student, a recreation director, foreign-car mechanics, a flight attendant, a riding instructor, a secretary and a jeweler.

Scott, a flat-water canoeist, had always wanted to ride the Whitewater in a kayak; he water-skis as much of the year as possible. Tom swims every day and thought it might be fun to venture into a kayak. Almost all of us in fact, were really fond of the water and had been in one kind of a boat or another.

A kayak is much like a cradle in the way is surrounds the body; sitting down inside it with feet and knees pushed against internal braces and a spray shirt attached to the waist and to the coaming of the deck, the paddler actually wears his craft.

Getting into this position, however, proved to be more difficult than slipping into a cradle. Some kayaks, it seems -- those with a rocker-shaped hull -- are affectionately called banana boats, and indeed, entering one can be like stepping on a banana if it is not done correctly. Mike demonstrated how the paddle is placed behind the cockpit and used as a brace while the kayaker gently glides himself into the boat.

Then, grasping the paddle shaft with both hands, he showed us the sweep, the basic turning stoke; the side brace, used effectively as a stabilizing stroke; and the wet exit, used when the side brace is not effective and the kayaker has not yet learned about the 360 degree eskimo roll.

Soon we were all in our boats, off paddling -- and in the water. The wet exit requires the unfortunate kayaker to calmly assume the fetal position as he dangles upside down from his boat, pull the release loop on his spray skirt, gently push against the kayak with his feet, and buoy up to the surface. The whole procedure takes perhaps 10 seconds -- if memory goes back to the womb. Some of us, however, could not remember back that far and instinctively thrust our bodies backward, thereby ensnaring ourselves in the spray skirt. After each capsize, the paddler must drag the kayak to shore and tip it several times from one end to drain out the water. We call this procedure burping the boat.

From the put-in point we angled our boats upstream to a pool in the river to practice eddy turns. Already we had learned there is no such thing as a lazy river. Even in a placid spot like this, the current, as it diverges around a boulder, creates a counter-current. The line where the two meet is called an eddy line, and going over it can flip a sensitive kayak unless the paddler is aware and uses the line to execute a slick turn to the apparent upstream. To get out of the eddy, we maneuvered downstream toward its tail and kept on paddling -- right over to a safe little cove.

The ducks of our group then headed upstream to practice their new turns in a more turbulent eddy. The chickens formed the cove clutch and practiced keeping their kayaks in one spot. When the ducks returned, Mike, Bob and Gail herded their flock downstream. Paddling with the current, we discovered, was easier than paddling against it, but not much.

Sweep to the left, sweep to the right -- finally we maneuvered our boats into a cove downstream from the inn and dragged them to the riverbank to take a lunch break. We sprawled out, soggy and exhausted, on the warm dry rock.

Amazingly, all of us still had semi-dry lunches stowed in the stern of each boat; they somehow had not fallen in the water or been lost during a burping. Accompanying the sounds of our munching and chatting were the splash of an occasional paddler gliding through the water, the wave of an soprey winging overhead, the hum of a breeze puffing through the woods. Even the river flowed clear brown, with underwater visibility of a few feet. A blue-and-black swallow-tailed butterfly fluttered among us.

After a brief rest, we straightened out our spray skirts, swallowed hard to calm the butterflies in our stomachs, and carefully donned our kayaks. We were off to Offutt Channel and Class I water.

Whitewater rivers are divided into six classes, determined by the terrain of the riverbed, the swiftness of the current, the elevation drop and the volume of water flowing at any given time. These ratings are subjective; says Bob Bailey, of Washington Whitewater, "The rivers are rated by whoever writes the guidebook." To an experienced kayaker, Class I whitewater, considered beginners' water, is little more than energetic gurgling. To a group of 10 novices, however, it was a test of how well the morning's lessons had been learned. Mike explained that the most important thing to remember in going through whitewater is to keep on paddling. Then he and Bob paddled off beyond the channel and stationed themselves on each side to yell out directions and encouragement.

A few members of us expressed a lack of confidence in our ability to execute the strokes we'd been taught. Inefficient strokes could make the instruction to keep on paddling a real challenge. Scott was a little more prosaic about his fears: "The only thing between me and confidence," he laughed, "is falling in the water."

And indeed, a few of us did end up floating through Offutt Channel instead of running it. One student hit a rock midstream, spun around 180 degrees and ended up bouncing through the whitewater backward. Fortunately, only the kayaker seemed to mind the switch; a kayak is perfectly willing to reverse its bow and stern.

Once everyone had recovered, or was recovered, from the stretch of Class I water, the flock ferried -- paddled at an angle to the current -- across the Potomac to the Virginia side, a distance of little more than a half a mile. Some of us, however, probably paddled almost a mile as we tried to keep our kayaks from turning with the current and going in circles.

With paddles hanging loosely from limp arms and helmets cocked like berets, we called for a rest. "Yellow Falls is next? Mike, can you order a helicopter?" Lacking air support, Mike told us that if we did not want to run the rapids we could portage around it. Four of us decided to forego the thrill of whitewater to learn this dry-land aspect of kayaking. The path around Yellow Falls is part of the riverbed in higher water. Walking across the rocks with a kayak and staying upright, we found, was almost as difficult as paddling through the rapids without capsizing. We had simply chosen to be upside down on land.

The nice thing about a kayak is that you can sit in it, and so once on the other side of the falls, we climbed into our boats, huddled in the cove and waited for the ducks to shoot the rapids. Only two out of six flipped in Yellow Falls -- well, better luck at Stubblefield. We were all going to need it: Mike said there was no way to portage there.

Approaching Stubblefield Falls, we could see the Cabin John Bridge looming across the river in the distance. "Oh, no, civilization!" someone called out. The faint roar we heard, however, was not of traffic but of water rushing down over rocks. It's a sound people will drive hundreds of miles to hear, pitching their tents within earshot of a falls babble; but the prospect of being in the falls evoked fear rather than tranquility.

Though not as wild as Yellow Falls, Stubblefield would be our longest stretch of fast water, offering a series of standing waves. Bob told us both rapids would rate a Class II to III on this particular day. As we bobbed together midstream, bumping boats and paddles, Mike laid out his plan to the four students who unashamedly admitted they were afraid to go through this one. It was simple -- Bob would escort one pair and Mike would follow with the other two.

Leaning forward, we began paddling -- easy at first, advised Bob, so we'd be strong in the rough water. Aiming for the center of the falls, the three of us hit the whitewater simultaneously. "Sweep to the left! Harder! Brace on the right!" The waves, about two feet high, tugged at our kayaks. It was all over in less than two minutes; we had made it through, without spinning or tipping.

And at last we realized the lure of Whitewater. For a few brief moments, secure with Bob paddling between us, we were riding a giant tilt-a-whirl, but we, not the carnival man, were in the control. Working our kayaks, we had challenged those small menacing mounds of water, and we had won.

From here it was an "easy paddle," Bob assured us, to the take-out at Lock 10. The definition of an easy paddle, it seems, is one in which the kayak as usual persists in turning in the wrong direction and going in circles ("You must have a left-handed boat," Bob told one of us) but the water is calm enough that it doesn't matter. Exhausted, we staggered through the trees to the takeout point. Scott angled his boat in last, with at least a dozen wet exits on his record.

"Well, we all survived," observed Karen. "What do you think?" A few days later, after talking with most of the group, she answered her own question: "Yes, we're going to do it again, but we're not going to do it like that again." She thought the day had been too long and the students too many for one instructor. And she advised prospective kayakers to "get over the dunking fear" before they spend a day on the river.

On the other hand, Mark, a graduate of three Washington Whitewater trips last year, "had a real good time" each time. "The most important thing," he says, "is getting comfortable in the boat. By the end of that first day I was doing a lot better."

In all his classes, Mark found three groups of students: those who caught on quickly and enjoyed themselves, those who had a good time in spite of not catching on, and those who became frustrated and disgusted.

"The biggest problem I see," he says, "is the diversity in the people who come out for a class -- people who are athletic, people who are interested in kayaking as a sport and those who just want to talk about it or who try it because a friend asked them to come along."

For those to whom sports do not come easily, or who still have the dunking fear, perhaps a few trips to a swimming pool or a Walden pond would be the best way to try on a kayak.Since these strange boats work better in a current, techniques learned in still water actually seemed easier on the river.

Probably more suitable, then, and less exhausting for timid beginners would be Washington Whitewater's two-hour evening sessions on the Potomac. In these classes of no more than six students, the techniques taught in the day trip are presented but participants do not run the river. In addition, a novice kayaker can join the Canoe Cruisers Association (send $10 to P.O. Box 72, Arlington 22216), which offers Whitewater-boating instructions and weekly introductory paddling classes on the C&O Canal throughout the summer.

One grand day in May, 10 boating enthusiasts met at Old Angler's Inn for their first day of kayaking on the Potomac. Four of them were afraid all of the time, and all of them were afraid some of the time, though for most the thrill of whitewater occasionally managed to penetrate their fear.

"If a man must be obsessed by something," writes E.B. White, "I suppose a boat is as good as anything -- perhaps a bit better than most." White's experience was with sailboats. We had learned that with kayaks, it is not enough to be obsessed by boats; you must also be obsessed by the water.