Two men out enjoying a day of fishing off the coast of Destin, Fla., were afforded a surprise encounter with the world’s largest fish species.

In multiple videos sent to AL.com by Cory Kauffman, a whale shark can be seen approaching the boat from which Kauffman and companion Jacob Nixon were fishing.

Kauffman said they were about five miles south of Destin East Pass when they spotted the whale shark, which stayed at the surface for about 10 minutes before disappearing into the depths.

Kauffman said he had seen whale sharks before during a visit to the Galapagos Islands, but never in the Gulf of Mexico.

According to the National Oceanic and Atmospheric Administration (NOAA), whale sharks are known to inhabit waters of the northern Gulf during summer and fall months, feeding on plankton, krill, fish eggs and small fish. They are filter feeders and pose no threat to humans.

It’s unknown how frequently whale sharks are spotted near the Florida Panhandle, but according to Greg Graeber with the Dauphin Island Sea Lab, while whale sharks are not uncommon in the Gulf, seeing them so close to shore is a rarity.

“Within the shelf region of the northern Gulf, they’re uncommon and five miles from shore is pretty close,” Graeber said. “As the largest fish species in the world, the fisherman had a pretty awesome encounter and maybe a once in a lifetime experience.”

Whale sharks are not whales, but they are a shark and the world’s largest fish, typically ranging in size from 14 to 46 feet (the largest ever recorded was over 67 feet) and weighing up to 24,000 pounds, according to NOAA. Whale sharks have been documented living to the age of 75, but it is thought they can live beyond 100. Although they move very slowly, their large size allows them to migrate great distances.

Whale sharks are considered endangered by the International Union for the Conservation of Nature. Two of the massive fish are in captivity in the Georgia Aquarium in Atlanta.