The veteran was being very gentle and complete with thenovice. He talked about pace, and about which side to paddle on, and he went over what the simple instructions would be while under way.

As the pair chatted high on the rocks over Wet Bottom Chute the teams of paddlers went off below at one-minute intervals. One by one they swept up to the line and waited for the succinct call of the starter.

"Fifteen seconds . . . five, four, three, two, one, go. Go go go!" And they were off, stroking madly toward the hole between a rock and a back eddy and on the raging, bucking currents of the spring-high Potomac.

"We'll take it nice and easy," said the veteran. "Nice, easy pace, and if you get tired just take a little off it.

"But there is one thing. Toward the end you'll be feeling very tired and your mind will be screaming at you to stop. Your arms will ache, your back will ache, you'll feel like you can't go another inch.

"When that happens," he said, and the novice prepared for a reprieve, "I just have one thing to say:

"Don't stop.

"If you do, then I will be paddling you. That's when I start freaking out."

There are no reprieves when the Canoe Cruises Association stages its annual 7 1/2-mile competitive blowout on the potomac. The literature rattles on about a great race for youngsters, for old-timers, for neophytes. But when that "go go go" is ringing in your ears you might as well be at the Olympics. And if you forget, the guy in the stern won't waste any time reminding you.

I was the novice last Sunday ana my cruel taskmaster was the wiry John Lentz, who made the mistake many years ago of entertaining one of these races on a lark and proceeding to win a second-prize medal. He's been lusting after the blue ribbon ever since.

So it happened that we found ourselves bouncing merrily along in the pounding waters, and soon it developed that we had successfully negotiated the perilous white-water stretches. Lentz carefully guided our 17-foot Grumman through the sluices of Wet Bottom, Difficult Run, Yellow Falls and the Stubblefields.

That accomplished, we plunged along through the long miles of flat water, stroke/pause, stroke/pause, and in the course of this hard, meandering voyage managed to pass nearly a dozen of our competitors. The numbers on their backs told us they had preceeded us at the starting line and we were doing swell.

Swell, hell. Each successful passing, it soon became apparent, did nothing but broaden our horizon to include the next team of paddlers sweating it out ahead, and each new boat brought more rumblings from the rear.

"Come on, we can catch 'em. Now we've got something to shoot for," said the irrepressible Lentz. The pattern stretch on and on into infinite strokes, as if we were inexhaustible machines with chrome steel shafts and bearings, oiled and fueled by an endless power source.

But we are human. Before long my strokes were mere charades: Put paddle in, lift paddle out, put paddle in, lift paddle out. The pressure came unbroken from astern as the boat lurched forward with the skipper's thrusts, then rocked aimlessly with the bowman's empty pretense.

"This is it, time for the sprint," Lentz shouted happily as the tip of Sycamore Island, the finish line, hove into view.

Through glazed eyes I began to make out the forms of crowds along the island and (did my ears deceive?) claps and cheers of the assembled throng. The sounds drove us to final heights until with a sudden finality the cruel truth hurtled alongside and instantly by us.

It was another canoe - and old, brown, patched canoe. In it were two people, and they were wearing numbers that indicated they had begun this race some 10 minutes after we had. In the stern was a very strong man, perched in the classic "knee-high" position. In the bow, egad, was a woman.

They swept by us like a trolley, as they say in canoeing circles. The cheers built on shore as they plowed home. We did our best, but the spirit had left us. So had the cheers.

It turned out these behemonths were Frank Haven and Debbie Britt, who don't mess around. Haven is a former Olympic champion in flatwater racing and Britt holds up her half handsomely.

You could be beaten by worse.

And we don't have to wait till next year to try again. Next race, May 20 and 21, is the Seneca Slalom, 10 miles upstream from Great Falls, which is another of these so-called novice races.

Don't be fooled. But if you can't resist, write for your entry forms to Seneca Slalom, Canoe Cruises Association, Box 4116, Colesville, Md., 20904