AUDIE CORNISH, HOST:
Even at its best, surfing is a brief moment of joy. When a surfer rides a deep blue wave with its foamy white crest, she might stand up for just 10, maybe 30 seconds on a perfect Pacific wave. But at an unlikely spot in Maritime, Canada, surfers are riding waves for miles. Murray Carpenter reports.
MURRAY CARPENTER, BYLINE: On a brisk early fall morning, Melvin Perez is zipping up his wetsuit in downtown Moncton, New Brunswick.
MELVIN PEREZ: This is the Petitcodiac River. People call it a chocolate river.
CARPENTER: The Petitcodiac does something unusual. Twice a day, it changes direction as the huge tides of the Bay of Fundy push water back upriver. As the tide rushes in, it forms a tidal bore - a small but powerful wave that rolls inland for miles. Perez lived on the beach in his native Costa Rica, surfing almost every day before moving to Moncton two years ago. And as an avid surfer, the river wave caught his eye.
PEREZ: I'd say well, you know, this wave has a potential for surf.
CARPENTER: But locals warned him that it was dangerous and possibly illegal to enter Petitcodiac. Then one summer night last year, he was tending bar at a hotel on the river's bank.
PEREZ: I saw some guys checking in and - with surfboards, so I was curious to see where they were going to surf. And then right away, they say yeah, we're going try here, the Petitcodiac, the river. So right away I said you know, this is the opportunity that I was waiting for.
CARPENTER: The surfers turned out to be pros from California. They rode the tidal bore for two and a half hours, traveling 18 miles. ABC's "Nightline" even covered their ride.
(SOUNDBITE OF TV SHOW, "NIGHTLINE")
DAVID WRIGHT: They emerged from the Chocolate River like chocolate surfers.
UNIDENTIFIED SURFER: I think we're covered in mud.
WRIGHT: But completely elated, having set a new North American record for the longest wave ever surfed.
CARPENTER: Perez caught a shorter ride alongside the pros that day. And when they left, he kept on surfing. Today, he looks at his watch, says the wave is due any minute and paddles out into the placid river.
CARPENTER: A few hundred yards downstream, Catherine Dallaire joins a small group of tourists to watch the tidal bore. Dallaire, who manages tourism for the city of Moncton, says recent efforts have improved the ecological health of the river and changed the wave.
CATHERINE DALLAIRE: Since the gates have been opened at a causeway that was built a number of years ago, the river has been able to run freely. And so the tidal bore, the wave itself, is much larger than it has been in probably 30 or 40 years.
CARPENTER: As the wave comes into view around a corner, pushing upstream through steep mud banks, it churns the river to a creamy froth. Perez paddles into position and he's up and riding.
CARPENTER: Dozens of tourists are watching as the wave passes with Perez carving across the face. Dallaire says the city of Moncton is not encouraging others to come and ride the wave because of the dangers posed by water pollution, rocks, sucking mud and fierce currents. Entire trees sometimes pop up in the waves next to surfers. But Perez is out there, year round, when the tides are strong, catching muddy waves that roll on and on and on. Exhilarated after his ride, he says that's the beauty of it.
PEREZ: Ocean waves you can surf waves for maybe 10 seconds, 20 seconds maybe, maybe the longest - 30. The cool thing about here is that you can surf for minutes. It can be one minute, two minutes or maybe more.
CARPENTER: For NPR News, I'm Murray Carpenter. Transcript provided by NPR, Copyright NPR.