Kayaking took off in earnest in the 1990s. Equipment improved, making it easier, and the popularity of extreme sports pushed athletes to take on harder runs.
Old-timers say that means that there are young paddlers out there who take on tough rapids but have not had years of experience with techniques such as rolling themselves upright when the kayak flips.
"They gain a lot of confidence very quickly" now, said Jesse Reynolds, the supervisory ranger at Great Falls Park, "and I tend to think they assume themselves [safe in] situations where they aren't truly safe."
Still, most of the Potomac's paddlers love the serenity of the river's smooth, flat stretches and would never risk going over Great Falls.
The river narrows before Great Falls, speeding up the current, and then it drops through a series of cascades. Kayakers on one route usually regroup in calmer water just before taking the final plunge, a roughly 22-foot drop, that took the lives of Andrew and another paddler six years ago.
In 1998, Scott Bristow went over Great Falls and disappeared. Many paddlers believe that he was caught in the pressure from spinning water, pushed into a spot known as Charlie's Hole. His body was never found.
Steve Goudy, who was carrying his kayak on his shoulder up the steep path from the river Friday afternoon, said the falls are too dangerous for him. With his helmet still on and water dripping off his life vest onto the trail, he said, "I know people who have run it hundreds of times, but for me, it's not worth it."
Respect for the River
Even with every precaution, the river has unknowns.
Many hard-core paddlers are cautious, knowing the strength of the river and how much is hidden below the surface.
Jeff Jarriel, a 40-year-old kayaker from Gambrills remembers when the water level dropped enough to see the riverbed. "It was extremely scary-looking," he said. Near the falls, "there's a huge cavernous room underwater. I remember paddling by thinking, 'Oh my God.' You don't even realize it's there when the water's up."
Hydraulics form when water comes over a drop, such as a dam or rock, creating a wave that curls back and heads upstream. They come in different shapes and sizes, and kayakers sometimes play in the biggest ones they can find. Other holes are more dangerous, pushing a boater toward rocks or not letting go, with relentless pressure from the water.
"You look at the falls and you think, 'My God, why would anyone want to run this?' " said Charlie Walbridge of American Whitewater, which is headquartered in Silver Spring. "But most boating accidents are caused by much more boring things."
About 20 people died nationally last year kayaking whitewater, Walbridge said. The number of deaths increased from an average of seven or so after the mid-1990s as the sport grew but has held fairly steady recently.
After the death in 1998, a group of paddlers, police and rangers developed a set of distress signals so that people in the water could communicate with rescuers.
Expert kayakers scout rapids, map their route, read the waves, plan what they'd do at each spot if they got in trouble, and go with a friend in case of the unknown, said Mac Thornton, a longtime paddler who helped found the Potomac Conservancy.
This year, five people drowned along the stretch of river near Great Falls; Andrew was the only kayaker. The other kayaking fatality this year occurred farther down the river, on a quiet stretch well south of the city. Michael Schoenfeld, a 62-year-old administrative law judge from D.C., drowned this month, his life jacket on.
Those who paddle in the whitewater have to respect the power of the river, Preston Hartman said. "We're in the river," he said, "so we understand the hydrology. The Potomac's a big river. It's very powerful. That's one thing that's so great about the sport -- just being in all that power."
Paddling toward the falls is like rising to the top of a roller coaster, the moment before the drop, said Joel Meadows, a kayaker from Virginia. The sound of the falls is thunderous, huge rocks jut out of the water, and the horizon suddenly appears through a cloud of mist.
It's too strong to fight. So a paddler takes a leap of faith: The kayak shoots off the edge and drops to the water of the Potomac underneath.
Jarriel said it's like standing next to a railroad track when a freight train rushes by. "You get that sense of raw power when it goes by you. Great Falls is like that, this amazing, big and powerful thing."
Staff researcher Bobbye Pratt contributed to this report.