PHILADELPHIA (AP) -- The Mason-Dixon Line seemed to take a detour north Thursday. At 6 a.m., with the sun just rising under the Tacony-Palmyra Bridge and country music blaring over the Delaware River, 106 big trucks towing 106 of the finest fishing boats to be had - $75,000 per, with sonar, radar, electronic charts - pulled into the Frankford Arsenal boat launch. Within the hour, 106 of the nation's top anglers, including the South Jersey bad boy favored to win, had gunned their 250-horsepower engines and roared off. Their quest: the river's elusive bass. The Bassmaster Elite, where the nation's top bass anglers are vying for $100,000 in prize money, is making an uncommon stop through Sunday on not just a Northern river, but also one of the nation's most urban. It's enough to turn heads in and out of the fishing world. What in tarnation?! A city? There's fish in there? "The Delaware River is a great bass fishery," said Pete Gluszek, a Mount Laurel angler and fishing guide on the Delaware. "A lot of people don't realize they're right here in Camden and Philadelphia and Trenton. They have adapted to living in the commercial structures," such as docks and pipes. Indeed, the tournament's choice of the Delaware is seen as a prime opportunity to celebrate the river's resurgence. No longer is there a dead zone near the Ben Franklin Bridge as there was through the 1970s, when oxygen levels were too low for fish to survive or even migrate through. The water is clearer, cleaner, and full of the hydrilla and other grass that make good bass habitat. Larry Needle, executive director of the Philadelphia Sports Congress, part of the Convention and Visitors Bureau, admits he was "as surprised as anybody" at the notion of a bass tourney on the Delaware. But, he added, "if it's good enough for the top 100 anglers in the world . . . that's a special thing." The tournament's Alabama-based sponsor, B.A.S.S., contends bass is the most pursued fish in the nation. And B.A.S.S. has declared itself the worldwide authority and "keeper of the culture of the sport." It does this through wildly popular TV shows, a website, and magazines -- readership for just one is 3.4 million. Top anglers have become superstars, their boats and bodies plastered with so many fishing logos that many liken the tournaments to "NASCAR on water." At 6:15 a.m., Missouri's Rick Clunn cruised by the dock to log the first start of the day. Then Mississippi's Paul Elias. "Unbelievable, to see this here," said Todd Pride. As managing director of the Mid-Atlantic Youth Anglers and Outdoors Program, he uses bass fishing -- and all its complexities -- as a way to aim urban kids toward college. Soon came "the biggest favorite in bass fishing history!" according to the emcee -- Pittsgrove Township's Mike Iaconelli, known to his fans as "Ike." The tattooed 42-year-old who break-dances, listens to hip-hop, and lists his favorite snack as Little Debbie Honey Buns is both the bad boy of bass fishing and, some say, the best thing that ever happened to it. He caught his first bass, a largemouth, in the Poconos at age 12. From then on, he was hooked himself. Not to mention prone to hollering when he catches a big one. They call it "going Ike." That fervor has occasionally taken him into rough waters. Like the time he pitched a fit in a tourney and was disqualified from that day's results. But Iaconelli makes no apology. "That's just who I am. Very passionate," he said earlier this week after a practice day on the river. That energy is often what takes him to the next level. He turned pro in 1996 and has $2.1 million in B.A.S.S. earnings so far. Worth far more is the income from his 18 sponsors -- Toyota, Fishidy, Power Pole, Berkley Gulp. Sometimes, dozens of spectator boats will hover nearby as he fishes. "I can't wait to showcase this river," Iaconelli said before the tournament. He's fished the Delaware for 30 years and dived back into his voluminous notes to prep. He went on scouting missions with lures he modified so he could feel the tug of a fish, but not actually catch it. Hook one, and it won't bite for another two or three days. "I don't want to burn the fish," he said. All will be for naught if something known as the "home water jinx" hits. In 45 Bassmaster Classics, only twice has a person from the home state won. Iaconelli is nonplussed. "I'm going to fish hard," he said. "Let the fish talk to me a little bit." The biggest challenge of the Delaware is its seven-foot tides, said Gluszek, the river guide. A lot of water moves up and down the river, and the bass move with it. "The whole house moves," said California contestant Skeet Reese, who declared the Delaware "a beautiful, scenic river. . . . I just haven't found the fish yet." Bass live in fresh water, and Gluszek predicted most contestants would try their luck in the city and north, above where the river is salty. But he figured a few would gamble by racing two hours through the saltier estuary, then turning into freshwater tributaries like the Maurice River in Cumberland County. They'd escape the competition, but risk a rough trip back. "If the wind blows, the Delaware River can growl," Gluszek said. The point of the competition is to catch the most total weight. Each day, an angler is allowed five fish. Starting with No. 6, he swaps out the smallest. The one thing he can't do is come back with a dead fish, which nets an eight-ounce penalty. Years ago, the tournaments ended with a fish fry, featuring the catch. Now, "oh my God, that's like eating a coworker," said Michael Mulone, director of events for B.A.S.S. "The bass are our friends, and we want to put them back." And no chucking a dead fish overboard to hide it! A tournament "marshal" rides in each boat. After the weigh-in, the fish are released.