See Open Water and you’ll be afraid to swim in the ocean—and that’s just for starters. Chris Kentis’ thriller about a couple’s disastrous scuba trip will leave you fearful of lakes, swimming pools and bathtubs, and you probably won’t want to turn your back on aquariums or water coolers, either.

Blanchard Ryan and Daniel Travis play Susan and Daniel, a busy, cell-phone-and-laptop couple who squeeze a tropical getaway into their overbooked schedule. They hope the trip will renew their fraying relationship, and initially enjoy a dive at a reef called “Magic Kingdom.” But the tour boat crew miscounts the divers, so when the couple resurfaces slightly late, they discover their boat has left without them.

Open Water effectively preys on agoraphobics’ fear of open spaces, as the flat, featureless ocean proves worse than the middle of nowhere because the current carries Susan and Daniel ever farther from where they started. In addition, sharks frequently school uncomfortably nearby. Without warning, shark tails break the surface with a shocking splash, or a torpedo-shaped form moves just past them.

Open Water isn’t a “thrill ride” movie with polished jokes, dramatic speeches or set pieces that try to top each other. Kentis is more interested in sustaining a mood of sheer dread and succeeds superbly on that level, giving Open Water the tension of a masterful short story.

Susan and Daniel go from bitterly blaming each other for their predicament to bravely trying to protect each other when imperiled. Open Water shows a familiar kind of loving, long-term relationship tested by the worst conditions imaginable. At one point, Susan awakens from an exhausted nap to find herself inexplicably alone, and her sense of abandonment cuts nearly as deep as the fear of the nearby sharks. In fact, Daniel had fallen asleep and the two drifted apart—literally.

Open Water doesn’t specify whether Susan and Daniel are married. Suffice it to say that they start out as lovers and end up as potential chum.

This review originally appeared in Creative Loafing.

OPEN WATER (Three Stars)
Directed by Chris Kentis
Starring Blanchard Ryan and Daniel Travis
(Rated R, 79 min.)