Whitewater canoeing can be more fun to watch than to do.Sitting on the bank, a spectator will often see what's going wrong before the canoeist can, and what for the paddler may be a scary spill is just a thrill to the onlooker.

Washington is blessed with a big brawny river where world-class canoeists train and overmatched amateurs play, and there are plenty of good spots to watch from.

There are five good areas within a short drive of downtown, if you're willing to scramble over some rocks, and three more an hour away near harper's Ferry.

Each rapid has special features but the best in demolition derbies is White Horse, on the Potomac below Harper's Ferry. There you can see every conceivable way to capsize a canoe and a few unthinkabler ones. At Little Falls, closer to the city, you can check out a dozen ways to demolish a kayak.

The string of rapids below Great Falls is the Great White Way, and the stars are the small, agile kayaks and C-1s and C-2s, decked canoes that look like fat kayaks.

Wrapped up tight against the river, they can plow through deep holes with spray and foam leaping around them leaving nothing visible but helmets and hands, or use a suckhole to stand on end and do cartwheels.

Decked boats are prima donnas -- temperamental and prone to capsizing, so their paddlers must learn the "Eskimo roll," a maneuver that continues the rollover until the boat is upright again.

In the hands of experts,though it is the open canoe, America's first watercraft that is the most beautiful to watch. The precise timing of paddle strokes, coordination of body movements and union with the river can be poetic. In the hands of average paddlers, however, this least forgiving of all the boats can create comic spectacle.

Advanced canoeists call overbold beginners "turkeys," and there usually are flocks of them out in rented canoes on waters where they don't belong. To spot one in time to call "camera," look for a boat in which the paddlers sit on the seats even in rapids, switch paddling sides back and forth, both often on the same side. They're likely to be stroking forward, too -- the rougher the rapid, the faster they flail -- and, at the peak of the crisis, they'll grab the gunwales. What comes next is a long drink of water. Hunkered down against a rock raking pictures of friends sliding, slamming and crashing through a foaming tummult recently, a Marylander fell into conversation with a lady from Ohio. The lady had happened on the action and was enjoying it, she said, "But your group's no fun to watch. Nobody's turning over."

The Marylander apologized and promised to try to do better next time.

"Doesn't matter," replied the lady, "we're going on shopping now. Besides, we saw three crashes in a row before you got here."

River Safety Officer Bill Kirby at Great Falls Park cautions that you need sturdy shoes and comfortable clothes for safe rock scrambling. Make sure you're in a secure spot before setting up your camera or binoculars and stay out of the river. Swimming is forbidden because the river in that section is a killer. There are dropoffs within a foot of the shore where boiling currents have swallowed many a strong swimmer; sometimes the river doesn't even give the body back.

The best spectator rapids are listed in order of their distance from downtown. All are on the Potomac except for Bull Falls and Roller Coaster on the Shenandoah near Harper's Ferry. Most locations are not safe for young children. LITTLE FALLS -- Action and expertise. Tough water, usually run in late summer when the river's low. Park near the overhead pedestrian bridge north of Chain Bridge on the Maryland parkway. Cross the canal to the towpath and go south toward Chain Bridge to a concrete sluiceway (looks like a roadway) angling to the right. Follow it to the river and head unstream. MARYLAND CHUTE -- A whitewater sampler where all kinds of boats line up to play in the narrow chute. Also used for teaching whitewater. You can get close to the action. Park at public lot across from Old Angler's Inn on MacArthur Boulevard or at Grat Falls Tavern, both on the Maryland side. Take the blue-blazed Billygoat Trail to the southwest corner of Bear Island. WET BOTTOM CHUTE -- All kinds of boats playing, but more difficult to reach. Action, beauty and a little demo derby. From Maryland, also off the Billygoat Trail. From Virginia, the last of three rapids reached by the Blue-blazed trail from the Great Falls Visitors Center. O-DECK -- Aerial acrobatics like popups, enders, surfing; a playground for the champs when the water is low. It is the rapid just below the second observation deck at the Great Falls Park in Virginia.

Two more rapids can be seen from the O Deck area. Rafts and some boaters run them, but you're not likely to see much playing there. They are called Fishladder and S-turn, and are on the way to: ROCKY ISLAND -- Also called Double A Gorge. Big waves and lots of show-stopping aerobatics at normal water levels. Center ring for the experts, with few amateurs bold or stupid enough to try it. The big waves really bounce rafters. WHITE HORSE -- The most action of all kinds on the Potomac with rafts, boats, hot shots and turkeys. It is on the Maryland side of the Potomac about halfway between the railroad bridge at Harper's Ferry and the U.S. 340 Bridge. Turn south on the first intersection before the 340 bridge in Maryland and follow the signs to Sandy Hook. Do not try to park in Sandy Hook.

Instead, drive through Sandy Hook, past the end of the railroad tunnel and under the old railroad bridge to the abandoned white house on the right, then park wherever space is available. Cross the dry canal bed to the towpath, turn south. The first rapid is Mad Dog, marked by steel girders sticking out of the water. White Horse is some 200 yards beyond and closer to the towpath. It has a large rock island in midchannel and a sudden drop in the river. The action usually does not begin until after noon. ROLLER COASTER -- A little of everything except demolition derby. yeasiest to reach since it is onthe Shenandoah opposite a sandy beach at Harper's Ferry parking lot. Park in the lot at Harper's Ferry nearest the bridge and walk to the river, then upstream to the stone viaduct. Roller Coaster is the long set of waves about midriver. BULL FALLS -- Second only to White Horse for demolition derbying since it is used as a teaching rapid.

Park in a legal spot near the Harper's Ferry end of the bridge across the Shenandoah. Look for the Park Service road, closed off by a gate, on the park side of the bridge and follow it toward the river to the abandoned railroad tracks. Walk upstream about a mile. Stay on the tracks; most of the land on each side is privately owned. When you get there, you'll see the boats and the three chutes through a jumble of large rocks. Bull Falls is the third one from the railroad track retaining wall. Stay on the wall. A long walk, but worth it. THE FEEDER CANAL -- It's not whitewater but is the practice course for Washington's world-class racing team. Park below Brookmont Dam on the Maryland side (near Little Falls) and walk north along the towpath toward the dam. Look for a path leading left, follow it to the canal and the slalom gates. Early morning and late afternoon are the best times to catch practices (the team will be in Europe through July). TAKING WHITEWATER PHOTOS -- A long lens is needed except at Maryland Chute, and a tripod is helpful. ASA 400 film gives the most flexibility, especially if it's a bright day and you have a polarizing filter to cut glare. Most whitewater action can be stopped with a 250th shutter speed.

Near water, the glare tends to fool your light meter, even if it's not a sunny day. Meter off you hand or rocks with about the same lighting as the boaters, or just open the lens 1.5 to 2 stops. Or use a polarizing filter and believe your meter.

Watch the action a little before shooting. Try for faces as well as motion stops. Shooting down on a rapid dampens the water action; shooting from water level heightens it.