Transcript for New Surfing Hotspot: Muddy Canadian River
Surfers are famous for traveling great distances and taking great risks for the perfect wave. Right now, there are epic waves along the atlantic coast of europe. Check out these babies off of france. But tonight, you're going to meet two dudes who journeyed to an extremely surprising place for a wave like no other. Here's david wright. Reporter: Surf rider beach, mali malibu, califork california. A place straight out of a beach boys tune. The natural habitat of our heroes. I need a drink. Reporter: A pair of surfer dudes who recently took a real life surfing safari. The land of endless winter. That's right, surfing in canada. When you're the only people on the river, surfing by yourself for 2 1/2 hour, it's a different story than coming up out here with 200 people and getting a 30-second wave. This is like rush hour on the 405. Exactly. I think most of the people on the 405 were coming here. Reporter: Colin and j.J. Were pioneers of the tidal bore on the kodiak river in muncton new brunswick in the great white north. It lies just beyond maine on canada's east coast. The petitcodiac river, home to the highest tides in the world. Twice a day like clock work, something strange happens. At high tide, the bay stills back into the mouth of the river against the current. A huge wave shoots back up the river for miles. A tidal bore, a phenomenon that happens only a few places on earth. The bore was famous back in the day. It would sweep boats away. AND THEN IN THE 60s, THEY BUILT This dam and stopped the flow. And the river turned into a stream. Shallow, clogged with silt and polluted, the water is now dark brown, like a chocolate river. It was something out of a willie wonka fantasy. People lived there for 60 years and didn't put a toe in it. New brunswick removed the dam hoping the river would come back. But the locals think of the water as toxic. Nobody swims there. So when these two california surfer dudes rocked up from the canadian border, the custom officials were skeptical. So what is this in the boot, eh? We're going to go swim a river wave in canada. Seriously, don't lie to me. We're going to surf after river wave. So literally an hour later -- Reporter: Go drop your trousers. Reporter: But as you probably already gathered, they're charming guys. After driving all night, they arrive just in time for the tidal bore. And we pull into muncton. We didn't even sleep the whole night. And the photographers are like you guys ready? We're like ready for what? Let's go right now! It's coming! Because it's time. Reporter: They're off. On the longest ride of their lives. 20 miles. How long did it take? 2 1/2 hours or so. Yeah, 2 1/2 hours. We're standing, paddling, running. You know, like riding prone. It was a triathlon of surfing. Ing look out, they could see the locals gathered on the banks, mesmerized by thf sight. It was pretty cool. It was amazing. I think it's incredible. I might get down there myself. Reporter: Truly a world away from southern california. Did you see any moose? No president nop the whole time. Nothing. . We saw bald eagles. They emerged from the chocolate river like chocolate surfers. But completely elated having set a new north american record for the longest wave ever surfed. To jump into a river smelling like poop and then smell like roses. Reporter: The brave ones joined right no. I didn't think it was actually possible without being thrown in jail, so when I heard that a couple of international guys were going to be coming in and doing it, I thought this was a perfect opportunity. At first, some local officials weren't all that thrilled. This is new to muncton, new to our citizen. It's dangerous. It's not for the uninitiated. Reporter: In the surfing world, nothing stays secret for long. It was really different than surfing the ocean. Gij jet here came all the way from norway to surf the bore, the first woman to do so. Just last month in frigid december intrepid surfers were still braving the bore. This guy is trying to set a record. He figures he's done it 40 times now. Muncton has warmed to the idea, so long as the surfers are state, delighted that their city is the whacky key of the great white north. Them telling the world how unique and amazing the experience was for us was absolutely priceless. Reporter: So you guys are honorary canadian citizens now? I think so. Reporter: Muncton, new brunswick, may not be malibu, but that's kind of the point. J.J. And colin have bragging rights. Reporter: Some of these canadians have never seen surfing in their lives. Whoa! Look at these guys. Jimmy: A gnarly wave on a chocolate river. But oh what a ride. I'm david wright for "nightline" in malibu.
This transcript has been automatically generated and may not be 100% accurate.