PADDLING THE COLD POTOMAC Lew Barker can be reached at his office, 857-3475, or home, 656-8376.

There was Tom Bash, game but dubious. What's the forecast for Sunday? If the air's 40 and the water colder, will a wet-suit and a sweater be enough? What'll keep my wet hands warm enough to move the paddle?

And there was Lew Barker, experienced, casual and patient with the doubters. The Potomac wouldn't be forzen over. Just the usual run from Angler's Inn, a few miles above the Beltway, to Sycamore Island, a few miles below. No rapids heavy enough to bother a well-paddled canoe or kayak. Nice day. Let's go.

So seven of us went, and when the paddle was over and when Lew said he'd run it again with us any weekend all winter long, the 5-2 verdict was: "Sure, let's do it again."

It was the first winter paddle for several of us, so when we began to plan for the Sunday with Lew Barker, our first concern was temperature: the river's, the air's and ours. We had all paddled a great deal on the Potomac in spring, summer and fall. We knew that the river above the city offered many miles of near-unspoiled outdoors and some marvelous rapid, ranging from big and bad just below Great Falls to bouncy and fun down to Little Falls.

We had all spent may days playing in the rapids or idling along watching the birds fly and the fish jump, and seeing the play of light over trees, water and sheer grey-rock cliffs. We expected it to be pretty - but pretty damn cold.

In all honesty, my hands and feet were cold. So were Tom Bash's. But a few others seemed somehow immune. Our one woman, librarian Shirley Kessel, wore nothing on her hands and said they felt fine, though they were wet from start to finish.

Stu Pettingill, an economist at the Agriculture Department, provided some warmth by telling us how cold it was to paddle on a real winter day. "At Petersburg last time," he said, "I had ice hanging on my face, and the only place where my paddle wasn't covered with ice was where my hands were. The boat was solid ice."

Stu wore a wet-suit and one-finger foam-rubber mitten. I tried them, and they did help - except for the hole in one thumb that let the cold water move in and out as my paddle dipped in and out of the water.

I also tried a pair of "Pogies" - heavy nylon hand-covers that attach to the paddle. You slip your hands in and grasp the paddle, and the nylon keeps out all of the wind and much of the water. But I was holding an aluminum paddle handle, and the metal seemed colder than either wind or water.

Most people in the group left their hands uncovered and seemed to do about as well as we more-cautious types did.

We all wore wet-suits. They're mandatory for winter paddling, since prolonged immersion in the Potomac's November-through-March water can kill the hardiest human beings: Lew won't take any paddlers without wet-suits on his weekend trips.

Most of us used the "farmer John"-style suit that covers your legs and body but leaves your arms and shoulders free to move easily witth the paddle. We wore sweaters and windproof jackets. They really did keep most of our bodies warm - except for our wet hands and cramned feet.

When we relaxed enough to stop worrying about the cold, we began to learn why Lew and his friends love winter paddling: the solitude. Like ski-tourers, winter paddlers are more alone. The skiers who crowd the lifts and slopes don't fill the woods where the touring skiers go. While Washington rivers aren't as crowded as ski slopes, a lot of summer paddlers do turn out here, and you have to wait in line at some popular rapids.

On our winter Sunday we saw no one nearby but two fishermen. Fifteen minutes from our homes, we had found solitude.

And Mother Nature offered us some uncommon bonuses. There were Vs of ducks sporting around us throughtout the trip. They seemed to play games, with us and with each other: A group would take off with great splashing and quacking and jockeying for position in the V, sight-see for a while and then come skidding in near us with more quacking and splashing. Norb Jaecks, who paddled an open canoe, said he guessed they were mostly wood ducks. Lew said that winter brings geese and even swans to the river's broader stretches. We didn't see any of them, but we did see a number of heron standing watch or flying slowly up the river and slowly back down again.

Another winter bonus is simply the change in scenery. When it's cold, the Potomac above the Beltway begins to lose its muddiness. Eventually, in late winter, the water clears up enough to look the way the first settlers probably saw it, so clear that paddlers can see rocks several feet under water. That's a mixed pleasure: In the summer you don't know they're there, but when the water clears up you see them and tend to forget that they're too deep to bother your boat. Your automatically dodge them, as you dodge all surface rocks in the summer.

And in the winter, the thick green foliage on the river banks turns red and then brown and then thins out to reveal the hills behind. The river basin takes a new shape and gives you new opportunities to think about slow geological change and quick springflood erosion and all the other forces that shape the Potomac banks. The air feels fresher, and you feel stronger in the winter.

For the practical paddler, there's another advantage to the winter: The river flow usually comes up to a more comfortable, more enjoyable level. Since rainfall is scarce during the summer and fall in the Potomac valleys upstream, the water level near the Distric drops, more rocks are exposed and the river turns sluggish.

But in the winter the rains come and the river rises and quickens. Paddlers love it.

Then there's the reason Steve Pringle's gave for joining us that Sunday. "My sport is soaring," he said. "In the winter, if the sun doesn't come out, there aren't any thermals to lift a glider, so there's no use trying. I figured I might as well get back into paddling."

Anyone who wants to try winter paddling as we did has a ready leader in Lew Barker. Lew works for the Red Cross all week, but on at least one weekend day all winter he'll take along any paddler who is ready for it.

You're ready if you normally paddle intermediate rapids in canoe or kayak, if you have a wet-suit, and if you're ready to observe all the winter safety rules Lew sets.

If you cross one of the Potomac bridges and look down and see the river frozen solid, call him anyhow. On the coldest days, Lew paddles farther upriver - above Violet's Lock - where the Dickenson powerplant warms the water and keeps it free of ice.