"Grab a seat and hold on."

As the sun squints over the horizon, Keith Eshbaugh casts off from the dock and throws the Mercury engine into gear. He swings across the current, gunning straight toward preoccupied commuters on the opposite riverbank. The surrounding skyscrapers ricochet the buzz of our immaculate maroon outboard along the river. Rush-hour traffic blurs on the bridges that wrap overhead. Half-mile wakes from coal barges shouldering their way down the Monongahela lap at our stern as Eshbaugh turns up the Allegheny.

It's morning in downtown Pittsburgh -- and we're going bass fishing. Eshbaugh is showing me the site of the Citgo Bassmaster Classic, the world championship of pro fishing, to be held here starting July 24 (the big event is July 29-31). For most Northeastern city dwellers, this annual competition barely makes a splash. But for millions of angling aficionados, it's an all-American whale of an event.

More than 80,000 people attend the weeklong fish fest annually, the culmination of the pro tournament circuit. (While the Classic migrates nationally, it will be held only in warm water sites beginning in 2006.) And this time, though anglers can spread out for miles, fans actually might be able to watch the fishing: The confluence of the three rivers downtown offers spectators a chance to see the pro boats pull in the prizes -- from the water, the shore or an office window.

"Pittsburgh has become an amazing bass fishery," says Mike Iaconelli, a brash 33-year-old from Jersey. He's earned $776,000 on the pro bass circuit and hopes to grab the $200,000 trophy this year. "The downtown is definitely going to be a popular fishing site for us."

The city's rivers have more sparkle than in past decades, a clean-up prompted by 1972's Clean Water Act and the demise of the steel mills. Workers catch fish on their lunch hours at downtown Point State Park, where a century ago they'd be more likely to catch a disease: The city's filthy water had created the nation's highest typhoid death rate. Local ecologists now boast of 50 freshwater varieties in the Mon, Ohio and Allegheny rivers, up from 10 in 1968.

Pittsburgh's reclaimed riverbanks have turned from all work to more play. Kayakers paddling to Pirates baseball games at riverfront PNC Park dodge blue herons and crew teams, along with coal barges. Beavers toil near bikers on riverbank trails.

"What's the weirdest thing you've ever caught here?" I ask Eshbaugh, as he pilots toward the Highland Park Dam, beneath the city zoo. As the state walleye champion, he's plied these waters long enough to have some good fish tales. "A paddlefish," he answers promptly.

Paddlefish, prehistoric leftovers that look like cross-eyed sharks with two-foot spoons on their snouts, can't thrive without clean water (and the resulting good eating). Hooking one is living proof of river improvement. Bass, by contrast, thrive almost anywhere. The local ones average about two pounds, though divers report seeing some 10 times that size lurking below city bridge piers. To win the Classic, entrants catch five fish a day. The heaviest three-day total wins.

Eshbaugh throttles back in sight of the locks flanking the dam. Our wake surges forward as the boat dips. "Here's a good spot," he says. "These red buoys -- they've been good for years." As he baits our lines, he talks about a tagged fish, a West Virginia sauger, caught in the Allegheny after passing through eight locks along the way.

Most Bassmaster fans will travel even farther.

The 2005 Classic will be a red-state happening in a blue-collar downtown. Texas and Florida boast the largest state memberships in the Bass Anglers Sportsman Society (BASS), but Ohio, Illinois, North Carolina and Pennsylvania are now among the top 10. The sport is outgrowing its sleepy stereotype.

"It's high-energy, exciting, constant movement," exults Iaconelli, the 2003 champ. "A new generation of anglers has come on the circuit with new styles." His own trademark is a penchant for breakdancing after big catches.

Television has created millions of couch anglers. Bass fishermen have their own line-up of ESPN shows, including "Loudmouth Bass," "Bassmaster University" and the upcoming "Bass Tech" (a sort of "Pimp My Boat" for hands-on types). There are even an online fantasy fishing leagues. The daily Classic weigh-ins, with cheering fans packing the arena, are broadcast live on ESPN Outdoors, which owns BASS. "Fishing has been a solitary sport. Now it's a spectator sport," says Chicago fishing commentator Chauncey Niziol. "Soon there will be marshals to keep crowds away so the pro anglers can fish."

Out on the river, however, the old-fashioned lure of floating, casting, reeling and relaxing doesn't change. We drift past industrial plants and city row houses, willow-strewn islands and bridges, more of the latter here than in any other county in the United States.

Eshbaugh's fishfinder displays an ultrasound of the river bottom in lurid color. A fluorescent orange blip moving up the right of the screen is a fish, climbing the underwater ridge 12 feet below the boat.

Fishfinders are essential tools on the pro circuit, and they really help. Thanks to the electronic readout, I can see how completely the fish ignores the wiggly fluorescent bait I'm dragging in front of it.

Eshbaugh methodically pulls in drum, bass and the occasional knot of frayed rope, which bends his line in the dark green water exactly like a trophy fish. His live catches stay that way, in the boat's oxygenated well. (At the tournament weigh-ins, the fish also make a live appearance. After a bath in antiseptic and salt solutions to calm them down, it's back to the river.)

It's after noon as we speed back to the center of town. As we near the 200-foot fountain at the confluence of the rivers, the gothic glass towers of PPG Place catch the reflection of the green hillsides on the river's southern bank. From here, the old steel town looks like Emerald City.

With the sun overhead, the Point is humming with jet skis and sternwheelers. Cruisers idle in the Allegheny, their pilots waiting for stray Pirate homers to splash into the river, clowning for the Jumbotron. Eshbaugh slows as we reach the ballpark landing to drop me off. As I step ashore, a cheer goes up from the crowd. Just for a minute, I think it's for me.

Couldn't be. I didn't catch a thing.

For Pittsburgh fishing Details, see Page P9.

Christine H. O'Toole last wrote for Travel on Kansas City's jazz scene.

Pittsburgh's catch of the day: smallmouth bass. Dave Boslett, of Forest Hills, Pa., has been fishing in downtown Pittsburgh, site of this year's Bassmaster Classic, for three years.Pittsburgh angler Marty Sanders, left, shows Sean Brady the rock bass he caught in the Allegheny River.