Charles Gaddy was tuna fishing with his dad on Sunday, more than 40 miles northeast of Oregon Inlet, when he saw something he’d never seen before.

“I was just looking in the water, seeing if, you know, any birds or anything, and I see this big gray fish with white dots,” said Gaddy. “Just from reading books and watching movies as a kid, I was like, ‘that’s got to be a whale shark.’”

The 18-year-old said they circled it. He grabbed his GoPro camera and started recording.

“It’s just sitting there, swimming beside us. It really, truly was amazing,” said Gaddy.

Whale sharks are the world’s largest fish. They’re currently listed as endangered by the Union for the Conservation of Nature.

In the Western Atlantic, whale sharks are primarily found in the Gulf and throughout the Caribbean, according to Eric Hoffmayer, a research fishing biologist with the National Marine Fisheries Service. He said they’ve seen numerous whale sharks make their way up the Gulf Stream, ending up in the New England area in late summer and early fall.

“We had an animal last year that we tagged off Tampa and within a month was off New York, and cruised right past North Carolina about this time of year,” said Hoffmayer. “It’s not unheard of, but it’s not real common either.”

Gaddy recognized how lucky he was to experience a sighting.

“To be able to see one in person, especially locally, it’s very truly amazing,” said Gaddy. “It’s no doubt a once-in-a-lifetime experience, and I’m no doubt very blessed.”

If you do encounter a whale shark in the wild, Hoffmayer said, you need to be careful if you’re in a boat because they spend a lot of time at the surface. If you get in the water, keep a safe distance.

“Most people I’ve talked to who have encountered whale sharks, it’s like a life-changing experience,” said Hoffmayer. “It’s really cool to see an animal that large in the wild doing its thing.”

You can report whale shark sightings to the University of Southern Mississippi’s Center for Fisheries Research and Development. If you’re able to capture a good picture of a whale shark, you can see if it matches one already in a database by uploading the photo and information about the sighting online.