If you think fly-fishing is all about relaxation and peace, think again.

“A lot of people associate it with [the 1992 film] ‘A River Runs Through It’ — Brad Pitt out there making beautiful casts as the sun goes down and the beautiful butterflies are fluttering behind him,” said Utahn Thad Robison. But in “Fish or Die,” his new Animal Planet series, “We kind of reversed that. It really does turn into chaos.”

The title gives you an idea of what to expect. Robison and three of his friends travel to remote, dangerous parts of the world in pursuit of big fish with huge teeth. It’s a show about guys who fish, but it’s not exactly a fishing show. It’s more about the journey.

In Sunday’s premiere (8 p.m. on DirecTV and Dish; 11 p.m. on Comcast), Robison, Chris Owens, Brian Jill and Jay Johnson travel to the jungles of Bolivia, where they go 60 miles upriver to the foothills of the Andes in pursuit of golden dorado.

“We all love to fly fish. That’s our passion,” Robison said. “We really want to go to places where a fish has never seen a fly cast in front of its face.”

In Bolivia, a small, rather rickety plane carrying Robison and Jill needs repairs before it can make it to the jungle air strip. From there, they travel into an area filled with poisonous plants and insects, dangerous animals, vampire fish whose “teeth are so big that they actually protrude to the top of their head,” and indigenous people who, they’re told, might be cannibals.

On a river in a deep canyon surrounded by jungle, they hear an eerie hooting that could be animals, or might be humans.

“It sent chills down my spine,” Robison said. “We went dead silent and then turned around and looked at each other and said, ‘Holy crap — what is that?’”

They never figure that out, but other threats were more concrete. Johnson’s hand swells alarmingly after a bug bite; Owens develops a highly painful and hugely disgusting case of jungle rot on his feet. All so they can “get to this place to be able to, basically, just throw a piece of chicken feather tied to a hook at the end of the line at some fish that we’ve never caught.”

Don’t be surprised if you ask yourself — what the hell were they thinking?

“I asked myself that the whole time,” Robison said with a laugh. “We just like going to places that are really difficult to get to. And the fact that we’re not survivalists doesn’t really help the situation.”

That’s part of the appeal. They’re pretty much regular guys who know how to fish but aren’t trained to survive the rigors of the Bolivian jungle or (in future episodes) nine other countries, including Borneo, Greenland, Mongolia and Zambia.

They have guides, and they get help from locals. And that’s the best part of “Fish or Die” — the interaction between the four Americans and the people they encounter.

“There’s so much that we have learned with all these different native cultures and people and tribes around the world,” Robison said. “That is the biggest thing that I take away from every one of these locations that we go to, more than the trophy fish, to be quite honest.”

(Photo courtesy Animal Planet) Chris Owens, Brian Jill, Thad Robison and Jay Johnson star in “Fish or Die.”

You don’t have to be into fishing to enjoy “Fish or Die.” Although if you are, that’s a bonus.

Robison, who grew up in Bountiful and now lives in Salt Lake City, fly-fishes for trout in Utah, where “you get a 5-pound fish and that’s huge. You get a 10-pound fish and it’s a monster,” he said. “And we’re going to these places getting 200-plus-pound fish. If that doesn’t get the adrenaline going, I don’t know what does. It’s just complete chaos when that fish gets on the line.”

(They catch and release the fish.)

Not all the fish are 200-pounders — the golden dorado are a fraction of that — but they are all “apex predators.”

“Fish that have big teeth like that are going to be really challenging to catch‚ and they’re going to put up a hell of a fight,” Robison said. “Those are two very distinct qualities that we like to look for in these fish.”

Robison himself is living the dream — traveling around the world having adventures and fishing. And he’s got the support of his wife, Jennifer, their 7-year-old son and his five children from an earlier marriage.

“I was gone for almost eight months solid to film this,” he said, with just four or five days between trips and a two-week break for Christmas. “But my wife and kids are so supportive. It’s unreal how lucky I got — the fact that all of them just think that what I do is the greatest thing. They know it’s my passion and they support it 100 percent. Otherwise, I’d probably be single.”

His wife doesn’t hesitate, however, to point out that he spent more time with his three friends than he did with her over the past year.

“It’s like I’m married to her and three other dudes, because we spend so much time together out on the road and working together,” Robison said. “And she laughs at that.”

Jennifer Robison is also happy that “Fish or Die” got picked up by Animal Planet so that her husband and his pals aren’t just traveling the world on their own anymore. In every country they visited, the producers hired a medic to accompany them.

“That makes her feel so much better,” Robison said. “They follow us around in case we have a serious accident or Jay gets a rash.”