“I decided, you know what, maybe I should go try and swim with him. I might not be able to do it ever again,” Kreis told ABC News on Monday.
The intrepid teen described the ride to NBC 2 in Fort Myers: "When I started holding on I felt the whale shark it started moving itself, it felt the drag and it didn't really want me on there so I let go and that's it."
Though riding whale sharks is legal, Kreis' actions have garnered criticism from environmentalists.
“When people spend a lot of time and a lot of pressure on a fish, it takes away that slime covering and potentially has negative health impacts for the fish,” one marine biologist said.
2014: The Year in Music [PHOTOS]