When I told Fran about the upcoming beginners' canoeing lesson on the C&O Canal she said it sounded a lot like chewing gum lessons.

Maybe it is for some people. But after an evening watching the Canoe Cruisers Association's patient instructors dodge through a bumper-car jam of out of control vessels, it's clear there are plenty of people who have no idea what makes a canoe even stay afloat, let alone go straight.

"I'm amazed any of them learn," said David Thomson. "I spent years going around in circles before I figured it out,"

Those must have been troubled years, because Thomson's father, John Seabury, is one of the high-profile members of CCA, a man who used to canoe across the Potomac to work and who has flirted with every rapids from here to West Virginia.

The two Thomsons were out last Tuesday, along with five other stalwart CCA instructors, trying to pound some simple strokes into the minds of 70 or so neophytes trying their hand on the skinny double-enders at Fletcher's Boat House, just south of Chain Bridge.

If ever there was a town to learn canoeing in, Washington is it. The CCA runs these sessions every Tuesday from 6:30 to 8 p.m. at Fletcher's and every Thursday, same hours, at Swain's Lock up River Road in Montgomery County.

If anyone should be bitten by the padding bug, which many are, there are two advanced CCA courses waiting in the wings.

"If they do this all right," said Thomson the elder, "the next step is the Red Cross canoe safety course," which CCA instructors run on weekends. Then it's on to the CCA's own whitewater course, which includes hair-raising voyages down the surging Potomac below Great Falls.

All the courses are free, as is use of the canoes.

So what's the catch?

The catch is that CCA, the largest canoe club in the nation with somewhere around 2,500 members, is hoping newcomers will catch on, keep the paddling movement growing and eventually add their names to the CCA rolls. For that it's going to cost you.

Ten dollars a year.

"Some of the members really raised a stink when we went up from $7 a couple of years ago," Thomson said, "There's always a groan when we have to raise the rates."

And with good reason. In 1967 CCA dues were $3 a year. The club is outstripping even the federal government's inflationary spiral.

"Yeah, chuckled Thomson, "but at least we're doing something with it."

Indeed. CCA runs cruises down rapids throughout the area just about every summer weekend; it holds annual Potomac River whitewater races, runs the various classes and seminars and prints a monthly magazine, "Cruiser," with all the latest poop on the canoeing crowd.

The classes are getting so popular that there was a danger last week of running out of canoes at Fletcher's.Thomson was scurrying along the canal bank, looking for pairs of beginners to put together. By the time he finished 43 canoes were in various stages of upset for a mile up the muddy stream.

Interspersed were the instructors, sweeping along in their solo rigs, offering tips to baffled first-timers.

It was a beautiful night, calm and cool, and by closing time at least a few pairs had managed to put the bow on a target and keep it there a few minutes.

The only people going nuts about it all are the folks at Fletcher's, who are at the end of a wearying day by 6:30 when the hordes descend.

"Please," said employe John Murto, "don't make it sound good.We're up to our necks already."

For information on Canoe Cruisers classes write Classes, P.O. Box 4116, Colesville, Md. For membership data write Membership, P.O. Box 5572, Arlington, Va.