In the last decade a place called Difficult Run has blossomed into a convention center for Washington area canoe and kayak paddlers of every description from novice to expert. "The beauty of Difficult Run," said one paddler recently, "is that it's different every time you go." An inch or two change in the river level creates different chutes, eddies, riffles and rapids to fool around in, and no matter how many trips you make, there is generally something new to try. On a perfect October day, I took my new, beat-up, second-hand kayak to Difficult Run and began to appreciate the wonders of this small, convenient ledge in a long and powerful river system. Difficult Run itself is a small creek on the Virginia side, about two miles downstream from Great Falls. The creek is not where the paddlers go. The place they mean when they say Difficult Run is the series of rapids that spans the river just above the mouth of the creek. Every nonflood weekend in spring, summer and fall these rapids are occupied by practicing paddlers in little boats. Mostly they leave their cars at the public parking lot on MacArthur Boulevard across from Old Angler's Inn, a 20-minute drive from Washington, and carry their boats down to the river. The portage is easy and there is a sandy beach with quiet water to start off. The rapids lie about a quarter-mile upstream, around a sweeping bend in the river. In normal water levels the upstream run is against a mild current, and even heavy two- man canoes can make it easily. Many canoeists, in fact, put in at Angler's, paddle upstream to Difficult and portage around it, then paddle another 11/2 miles or so upriver to Wet Bottom Chute, portage around it and turn around for a whooping downstream slide back home. Kayakers have a different interest -- playing in the fast water. I had heard about "playing" for years but never appreciated the merits of this frolicsome sport until I tried it myself. Kayaks have the singular whitewater virtue of being able to go up a rapid as well as back down it. That obviates the canoeists' tedious upstream portages and creates a whole new way of looking at the river. A big problem with canoeing is that the only way to figure out the subtleties of a particular drop is to view it from downstream, where you can see how all the forces play themselves out. Unfortunately, you usually end up seeing it after you've crashed into the submerged sawtooth rock in the middle on the way down, and a lot of the time your attention is divided between studying the rapid and patching the hole in the boat. With a kayak the game is to nimbly dodge upstream, skipping from eddie to eddie, working into the teeth of a particular roller or pillow of water and holding the tiny, needle-shaped boat steady while the water thunders under and around it. You get a good view of how a river works. In a canoe, an eddie is a quiet place behind a boulder, usually on the edge of the river. Because kayaks are so much smaller, more maneuverable and lighter, any little rock in the river, even one in the heart of a rapid, offers refuge from the current. I found myself, a neophyte, doping out upstream routes and charging into the flow. Then I got to a big ledge and I couldn't see any way around it. A fellow came along in a patched-up kayak and scoped the situation out. He backed up four or five strokes, plunged toward the rapid at an angle and shot up to the top of the ledge. He hung there for a moment, paddling like mad, and finally went over the top. A few minutes later he came back down. "I want to do that," I said. "O.K.," he said, " second try I found myself flailing away on the lip of the ledge and could hear him hollering from behind, "Go, go, go." So I did. And it did. Success! Difficult Run almost seems made for kayaking. The quarter-mile width of the river at that point offers practically limitless opportunities to read the river and pick various routes up it. The better you are, the harder a route you select. There's a big, powerful chute on the Maryland side and smaller chutes all across to the Virginia side. I played for a couple of hours and wound up paddling home in a state of exaltation, soaking up the warm fall air and marveling at a crystal blue sky. And it didn't cost a nickel.

HOW DIFFICULT?

Depending on the weather, paddlers could get as much as three or four more weekends of sport at Difficult Run before fall turns to bitter winter. Those with wetsuits can continue on after that. Most folks stay an hour or two and then head off for other weekend pursuits, which makes it a convenient morning or afternoon diversion. The parking lot across from Old Angler's Inn is getting so popular with fishermen, C&O Canal hikers and paddlers that on pleasant afternoons it fills up and a line of parked cars stretches down the boulevard. The hike to Difficult Run along the Billygoat Trail is worthwhile, as well. To get there, walk from the parking lot down to the Canal towpath and then upstream several hundred yards to a sign pointing out the trail on the left. The trail goes all the way upriver to Great Falls, a serious trek.