An apex predator of the sea, Hollywood and audiences have had an enduring love affair with sharks. It was Steven Spielberg’s seminal Jaws that simultaneously birthed the summer blockbuster in 1975 and made people afraid to go into the water. Save for a few sequels and low budget copycats, though, the limited sub-genre of shark horror was a vast wasteland for decades. Until director Renny Harlin unleashed big budget action horror spectacle Deep Blue Sea in the summer of 1999, that is. A special effects extravaganza that delivers nonstop action sequences and unexpected, gnarly deaths, Deep Blue Sea holds a special place in the canon of shark horror.

Written by Duncan Kennedy, Donna Powers, and Wayne Powers, Deep Blue Sea shares more in common with Alien than it does Jaws. Of course, this shark film pays its respects to its godfather; Thomas Jane’s action hero Carter Blake pries a license plate from the mouth of a tiger shark in an early scene, a direct nod to the license plate found in the belly of a dead tiger shark in Jaws. But the entire setup of the film bears a stronger resemblance to Ridley Scott’s classic 1979 space horror. The lines between sea and space are blurred, with the skeleton crew of the underwater research facility Aquatica trapped inside as they’re hunted by intelligent monsters. Instead of a Xenomorph, though, it’s a trio of scientifically enhanced Mako sharks.

Samuel L. Jackson plays Russell Franklin, the equivalent to Nostromo captain Dallas (Tom Skerritt). Franklin is the level-headed straight man, a corporate exec sent to investigate the facility after a shark escapes and attacks a party boat. Franklin has endured harrowing, extreme situations in his past, and has the chops to rally this motley crew of blue-collar workers and scientists together to survive. Except, he’s taken out early and in a shocking way. Smack in the middle of a rousing battle cry. Harlin effectively keeps his audience on their toes, each death unexpected and in defiance of archetypal expectations. Not all of them go by shark, either. Shark wrangler Blake steps up to the plate as capable hero, Deep Blue Sea’s version of Ellen Ripley, but that wasn’t exactly the original intent.

Of all the deaths in the film (Stellan Skarsgard’s Jim Whitlock suffers a horrifically prolonged one), the only death that feels out of place is that of Susan (Saffron Burrows). She fights for her research and her life the entire film, only to give up and allow herself to become shark food in the finale. It turns out that wasn’t the original ending for Susan; she was supposed to be the Ellen Ripley of the story. In the original ending, Susan was the one to harpoon and kill the final shark. A test screening one month prior to the film’s release changed that. The test audience hated Susan. She was the one who violated ethics and masterminded the sharks’ creation, after all. Susan was seen as the film’s villain, not the hero. Last minute reshoots meant Susan died and Aquatica cook Preacher (LL Cool J) got to play hero with Carter. It was ultimately the right call. Though Susan’s experiments came from a place of good, she wasn’t given much of a redemption arc to earn her heroine title. Not even Carter forgives her until the moment she concedes they should kill the final shark, and by then it’s too late. Considering Carter displayed common sense from the outset, he filled the hero role better anyhow.

If there’s one thing Renny Harlin does well, it’s craft thrilling action with big budget flair. As such, Deep Blue Sea isn’t exactly high-brow, but boy does it entertain. There’s a gleeful sense of fun, as Harlin speeds from exhilarating action sequence to exhilarating action sequence. It’s a reminder that movies don’t always have to have profound depth or a statement to make to solidify their ranks as worthwhile cinema; just pure summer fun will sometimes do.

Deep Blue Sea was the first film Stephen King saw in theaters after nearly dying from a vehicular accident and he enjoyed every second of it. So did critic Roger Ebert. The point being is that there’s a reason Deep Blue Sea was profitable during its theatrical run, and why it still has a solid fanbase today. Harlin dared to bring the horror genre back to the high-budget ranks of films like Jaws, a rarity when horror has increasingly become relegated to low budget profit machines. Jaws may be the granddaddy of all shark horror films, but Deep Blue Sea proved action-horror, great special effects, and a strong grasp of suspense can be just as memorable.