Payson Kennedy was full of questions. "Do you know the peelout?" he asked. "How about the low brace and high brace? Do you do eddy turns? Are you used to ferrying? What's your basic stroke?"

We took turns mumbling inadequate answers while trying to keep our canoes from running away down the Nantahala River in western North Carolina.

One of us is a Maine native who was born with a paddle in his hands, and the other is pleased to call himself an outdoor writer and canoe enthusiast. But we were used to such basically placid rivers as the Potomac, Shenandoah, Cacapon and Rappahannock, where the usual problem is finding enough water to float a boat. The icy Nantahala, powered by the penstock of a hydroelectric dam, runs as swift in its rare "calm" stretches as the so-called rapids of most of the Washington region's rivers.

One reason the Nantahala runs so fast is that the Tennessee Valley Authority turns it on and off every day. During the daylight hours of peak power demand, the TVA releases as much water as used to be spread over 24 hours, when the river was wild. When the turbines are running, most of the rocks are well underwater. "It looks pretty fierce, but actually it's kind of boring," the writer's boyhood friend had said. "All you need to do is bail now and then." The boyhood friend will be scratched from the Christmas-card list.

We had dropped by Kennedy's Nantahala Outdoor Center, near Bryson City in the Great Smoky Mountains, to brush up on whitewater techniques before running Section III of the hellacious Chattooga River, made famous by the James Dickey novel "Deliverance" and by his readers who have died trying to run Section IV.

"You fellas appear to have been doing a lot of float-paddling, rather than whitewater," Kennedy said as he watched our clumsy efforts to follow his graceful examples. His battered boat, picked at random from the rental rack, danced and spun on the water. The difference was devastating: whereas we had gotten into our canoes, Kennedy had put his on.

"What's called for here is power, or, more properly, efficiency in stroking," he said as he pivoted his boat in what seemed to be half its length. "You don't have time to dabble around in these rapids; every stroke has to count."

After an hour of practice Kennedy led off downriver. He clearly was not satisfied with our readiness, but perhaps feared we were burning out. He had with him a large firstaid kit and what seemed at the time to be a much longer and stouter rope than we could possibly need.

Patton's Run, the first rapid, came too soon. Kennedy rates it a "low 3" (on a scale that runs up to 6), meaning that while adequate boat-handling is required to negotiate the crosscurrents and standing waves, there are no serious rocks to avoid and there is fairly quiet water below where you can get yourself and your boat back together. In the Washington area it would be called Class 4: skillful canoeing required to avoid minor injury and damaged equipment.

We avoided neither.

The water, drawn from the bottom of the reservoir, was shocking cold. Kennedy played around, running the river sideways while we put ourselves in order on the matter-of-factly named "Isle of Dumping."

"Actually, by staying with the main current and on the edges of the standing waves, you could run this river forever without any trouble," Kennedy said. "But you never would improve your canoeing. Shooting the rough parts and catching the eddies, attacking the river, is the only thing that makes it worth running. This is the easiest of the six or eight rivers around here that we guide raft and canoe trips on. It's a whitewater beginner's river, really."

He resumed his attack on the river, looking for trouble, leaving us to wallow behind in new-found humility as we watched him careen his boat in two-foot waves, practicing his recoveries; stop in the middle of roaring rapids; run rapids and "rock gardens" backwards; run up rapids; and show a school of kayakers how to "surf" an open boat in the hydraulic backwaters below ledges. They were impressed; we were awed.

Along the way he worked at teaching us how to make the most of the river; since it already was the most river we had ever ventured on, we were slow and timid students. Also, one of our boats was beginning to break up, and the other was scarred. Time and again Kennedy demonstrated some simple maneuver; time and again we failed to execute it. The closest he ever came to showing the impatience he must have felt was when he said to the outdoor writer, "You know, you really must take charge of your boat."

"It keeps taking charge of me," the student moaned. The first thing he had learned about canoeing was to keep the bow straight, downstream; Kennedy showed a calm indifference to bow placement, doing as he damn pleased whichever way the rapids ran;. It was a long time before the writer ventured to cock his boat even slightly off the line of the current, and he never did quite understand why the river did not immediately punish him.

If we could not reap full benefit from his instruction, we could at least appreciate it. Kennedy is a reformed University of Georgia professor (sociology and library science). He threw it all aside seven years ago - at the age of 43 - to start the Nantahala center because "At least all the students who come to me here want to learn." His program produced something like half of the U;S. medalists in the 1976 Olympics and seems likely to do even better in 1980.

It was rainy and cold, which helped us explain to ourselves why we were so pooped after only eight miles of river. It did not explain why Kennedy who was more lightly dressed and putting out at least twice the effort, seemed as fresh toward the end as at the beginning.

The end. The end of the Nantahala, for anyone but an expert or a fool, is Nantahala Falls, "a high Class 3," above Kennedy's headquarters. Below the headquarters is Wesser Falls, a high 5: probable serious injury, risk of death.

Scouting Nantahala Falls, Kennedy said it looks harder than it is. "You can run it almost anywhere from bank to bank, if you stay off the center rock. Best come in from the left and slide right. I'd say your chances of making it are three out of four."

It wasn't even close.The writer made the same mistake as the Maine man had made earlier, delaying until too late the move to the left. Moments later he was sluicing down the river, bouncing from rock to rock like a pinball, with Kennedy in pursuit. As it happened, the rescue rope was neither longer nor stouter than necessary.

Back on solid ground with the remains of our canoes, we stood shivering and inviting Kennedy for a cup of coffee. "Well, my partner and I usually work out this time of day," he said, and disappeared with a friendly wave and a word: "Practice."

After an hour or so we decided to take a walk, to see if we still could. Along the trail we met Kennedy and his partner carrying their canoe back from the workout. At Wesser Falls.

"You know," the Maine man said that night, "I really need to take my canoe back to the factory before I run any more whitewater. I don't think I'll have time to run the Chattooga."

"Me neither," I said. "Maybe next year?"

"Maybe." CAPTION: Picture, JOHN SEABURY THOMSON, OF THE CANOE CRUISERS, TEACHES CANOEING ON THE POTOMAC. By James M. Thresher.