A few weeks ago two canoeists, each with a decade's paddling experience were crossing a river in West Virginia when everything went wrong at once.

There had been a hard rain the night before. The river was cold, high, muddy and rising. But it was a familiar stream and they thought little of danger.

They paddled out in the shoreside eddy, heading directly for the far shore 30 yards away.

Suddenly they hit the roaring current. They paddled harder, thinking they could overcome the downstream force; but the canoe began to rock and in seconds the upstream gunwale had dipped under and they were shipping water.

"I'll tell you, it was harrowing," said one of the men later. "We didn't know whether to scream or go blind."

What they did do finally was to manage to get the canoe turned around, half-sunk with cold water, and struggle back to the home side.

Back in the cabin they did a little research and found out that in all their combined years of canoeing they'd never learned one of the basic maneuvers -- ferrying.

"When I figured it out," said one, "I felt like going up to total strangers on the street, shaking them by the collar and saying, 'Do you know how to ferry?'"

This is a wonderful time of year to go paddling, particulary when a mild blue-sky day pokes through the dreary winter scene; but it's a very bad time to start learning how to paddle.

Ferrying is one of those maneuvers that are crucial to safe canoeing, but unfamiliar to most paddlers -- even veterans. Here's how it works:

Think of what a canoe is -- a long, narrow, light floating object, like, say, a 16-foot piece of balsa wood.

Throw that object into a fast-moving current, broadside, and evision what will happen. No matter how much forward force you apply, the object is going to go tumbling downstream sideways.

But turn the oject directly into the flow of the current, apply the forward force and it's likely to hold its own, or lose ground only slightly, against the flow. In any case, it will be under control.

That's how ferrying works, basically.

The two men in West Virginia should have paddled out to where the current was running fast, then pointed the bow of the canoe directly upstream.

Once they were holding their own against the current, they would aim the bow about 10 degrees toward the shore they wanted to get to. As they kept paddling the current would gently ease them across until they reached the shore.

Ferrying is a weird sensation, because you're pointing the boat one way to get to a place that lies in another direction entirely. But there are times when it's the only way to get across, and it provides a real sense of satisfaction to have outsmarted the river when you can't just overpower it.

No one should be fooling with white water in the winter, anyway, unless he's an absolute expert. The Canoe Cruisers Association runs a few winter voyages, but around mid-November it starts ruling out any paddlers except experts wearing wetsuits, which is the only safe uniform for winter white water.

But flat water is something else. There are long stretches of the Potomac between Great Falls and Harpers Ferry that are as calm as lakes this time of year, and they can be a delight on a warm winter day.

A friend and I did eight miles on the river last week and came back grinning. We saw only one other boat all day.

Even in flat water there are some winter rules that ought never be broken. River water is well under 50 degrees now, and even a brief dunking, if there's no warm place to repair to, can be extremely dangerous.

Always wear a life vest when winter paddling, and several layers of clothes including some wool, which retains heat when wet. The surplus stores sell waterproof rubber sacks that are excellent for storing a change of clothes in case of accident. A good canoeist will carry such spares, and tie them into a thwart on the boat so they can't wash away.

No boat should be without a spare paddle, and no paddler should be without a wool cap and wool gloves.

A lot of hassle? It's worth it, to be alone somewhere between Point A and Point B, with nothing but ducks and woods and clear, cold water.