In any case, the ride was in production while the movie was yet to be filmed, which explains the aquatic theme. For those who haven't been to Universal Studios (or went but spent the whole time guzzling butter-flavored 7-Up in a magical boarding school), the ride loads passengers on a raft, then sends them down a lazy dino-filled river ride. But since Jurassic Park, not unlike Chipotle, is prone to one disaster after another, soon the dinosaurs escape! The ride culminates with a T-Rex head popping out as your boat plunges down an 80-foot drop! It's exactly like ... nothing that happens in any of the movies.
This is a direct reference to something that was supposed to be in the film -- a rafting sequence in which Grant and the kids narrowly escape a T-Rex attack. It was even storyboarded before ultimately being cut out and replaced with more coverage of Jeff Goldblum's glistening torso.
Universal Studios built a shit-ton of animatronic dinosaurs for the ride, and even hired Sir Richard Attenborough to reprise his role of John Hammond for the introductory video. Though, unfortunately, he writes off all the dino-murders in Costa Rica as a "wee problem" due to "sabotage"-- meaning that he was apparently faking that whole "Playing God is a bad thing" epiphany he had at the end of the movie.
Universal Studios Hollywood