Underwater is basically just Alien six miles down in the ocean. If your first thought upon hearing that is either Leviathan or Deepstar Six, there is no need to see this movie (although it's admittedly a bit better than both of those). Alien, by writer Dan O'Bannon's own admission, ripped off everything, so criticizing Underwater for a lack of originality perhaps isn't fair. Criticizing it for not being an entirely successful ripoff, however, is fair game.

Part of the problem is that it feels as though the first half-hour has been removed. Within two minutes, we're plunged into the plot, without any kind of proper set-up or introduction to the characters. Kristen Stewart plays Norah Price, one of a group of researchers working way below the surface in the Mariana Trench. Their facility is critically damaged by an earthquake. The captain, Lucien (Vincent Cassel), decides that the only way for them to survive is to walk a mile across the ocean floor to another facility that's been abandoned. There, they can hop in escape pods.

Several others make the trek along with Norah and Lucien. Of course, there's the requisite wise-cracking guy (T.J. Miller), along with a couple in love, Emily (Jessica Henwick) and Liam (John Gallagher, Jr.). We don't get to know any of these people or get much sense of their professional/personal relationships. Consequently, it's tough to care too much when it's revealed that some sort of never-before-discovered creatures are lurking down there. (Part of Alien's genius was that we understood how the characters related to each other before the terror began).

Whoever decided it was a good idea to make a movie on the ocean floor, where visibility is extremely low and silt kicks up whenever anything moves, deserves a figurative smack upside the head. Underwater is extremely difficult viewing at times, because you aren't always sure what you're looking at, particularly during the action scenes. That has the effect of muting what are supposed to be signature sequences.

Those issues are undeniable. In spite of them, the movie does succeed to a degree. Kristen Stewart and Vincent Cassel deliver good performances, even if we're sketchy on the details of their characters. Stewart brings a nice sense of subtlety to a profound choice Norah makes in the film's final minutes. You'll see it coming, but the actress makes it work anyway by avoiding the overwrought cliches many performers would have embraced.

Underwater additionally has a few reasonably thrilling scenes (i.e. the ones you can see). The implosion of the facility is tense, and there are moments that play on fears like running out of oxygen or being in a cramped space. Best of all is the finale, which offers a cool threat for Norah to face. No, it's not radically different from other things we've seen, yet it's handled in a way that's fun and exciting.

Underwater is one of those middling films that's as hard to hate as it is hard to love. It offers some passing entertainment without ever giving you anything to get too enthusiastic about.

out of four

Underwater is rated PG-13 for sci-fi action and terror, and brief strong language. The running time is 1 hour and 35 minutes.