After her first harrowing glimpse of the spot where our raft trip was to begin, Elissa the Fearful needed convincing. It was close enough to Great Falls to be showered by spray, looked treacherous and sounded like doom.

"Do we really have to do this?" asked Elissa, sitting on the rubber bottom of a six-person raft, seconds from the start of a ride she paid $26 to take. Her knuckles were already white. "I think this would be a great place to spend the day."

There were 26 of us in an armada of inflated, rubber rafts at the start of a five-hour ride down the Potomac River. Though only 10 miles from downtown Washington, our view from the Virginia shore was pure wilderness. And for most of us, it was the view, more than the promise of any wild ride, that had attracted us.

Our guide was Tom Springer, a middle-aged man with the body of a 20-year-old and a sense of humor that remained bone dry throughout the trip. After issuing basic paddling instructions to his crew, all of us dressed in life preservers and helmets, he launched us into the foam. The first few hundred yards were fast and rolling. Standing waves splashed the riders on the bow, who paddled hard to get around a rocky island that split the river.

Beyond the island, the river suddenly grew calm and the shore line steep. We had entered Mather Gorge, a canyon with sheer cliffs 60 feet high. As the raft slowed, Springer pointed out geological formations and related some of the human history of the area, from Indian fishing techniques to abandoned, 19th-century river towns.

"In the fall this river is a great migratory highway for birds," said Springer, who has seen deer, eagles and beaver in abundance while floating the Potomac. We passed an iron boat ring hammered into a rock face during the Revolutionary War. We rode below the remains of the Pawtomack Canal, built by order of George Washington in an attempt to make the Potomac a great river of commerce. The canal was abandoned more than a century ago.

River rafting has come a far, fast piece since Huck Finn floated the Mississippi on a logjam. Today's rafts are made of rubber and trapped air, designed to bounce off rocks and resist the suction of rapids powerful enough to swallow mature pines.

During the last decade, rafting outfitters have built a million-dollar industry on America's wild rivers, mostly by advertising them as roller-coaster rides and appealing to thrill-seekers more interested in riding waves of fear than water.

"Are You Ready for the Whitewater Challenge?" ask ads for raft trips down rivers with rapids dubbed Mash, Pure Screaming Hell and Meat Cleaver. "Come to the Devil's Playground."

In fact, there is no look of near-drowned terror more vivid, no tight-lipped grimace more easily aroused, than the expression that floods the face of my friend Lieb at the mention of the word "raft."

"I was sucked under so hard it pulled my sneakers off," said Lieb, a Washington attorney who was bounced into the boil of West Virginia's Cheat River minutes into his first raft ride. "I didn't know which way was up, but it didn't matter. The river wasn't going to let me go anywhere. I knew I was going to drown, at the bottom of a river I'd never heard of."

But river rafting does not have to be a flirtation with death. The quiet float down a clear, wood-lined river, wondering at all the flora and fauna you cannot name, is a thrill no amusement park can provide.

There are three outfitters within a two-hour drive of downtown Washington that offer float trips you can enjoy without keeping a death grip on a paddle. The guided floats, on the Potomac and Shenandoah rivers, are startlingly scenic and safe enough for a Mother's Day date.

"There's a lot of hype involved in the rafting business," says Jamie Welch, the manager of River and Trails Outfitters in Maryland, a 14-year-old company headquartered across the Potomac River from Harper's Ferry. "We downplay the big, white-water aspect of it and emphasize a lot of splashing and a lot of swimming."

The River and Trails raft trip begins on the Shenandoah, four miles above Harper's Ferry. It ends one mile below the historic, West Virginia town, after the Shenandoah has emptied into the Potomac. In spring and after a heavy rain, the ride can be fast and bumpy. During summer and fall, the river gets low and slow enough to require long stretches of paddling and occasional white-water hiking over rock gardens. Great blue herons will sometimes provide an escort down-river.

"We promote our trips as a whole river experience, the environment, the hydrology, the history of the area and the geology," says Tom Conant, manager of Blue Ridge Outfitters, a West Virginia company that offers guided raft trips down the same section of the Shenandoah. When Blue Ridge started 12 years ago, with a few rubber rafts in a a renovated horse stable, there were a handful of outfitters in West Virginia. Today there are two dozen.

Both Blue Ridge and Potomac River Tours of Bethesda share a Potomac river route that seems impossibly scenic to be just 10 miles from the White House. From the Virginia shore, just below Great Falls, the rafts cover six miles in as many hours, around densely wooded islands and through walls of granite 60 feet high.

"There's nothing on the trip that a beginner can't handle," says Gary Clark, a trip leader with Potomac Tours, who often has to reassure clients that they will not be eaten by this stretch of the Potomac, despite what they have heard, and perhaps wish to believe.

"People who are most terrified usually have the best time," said Clark. "When they realize their fantasies are unrealistic, they can relax and really enjoy it."