Writer-director Chris Kentis's minimalist nail-biter Open Water invites audience scoffing at its leisurely outset, marked by bland characterization and the hazy patina of blown-up digital video. But only seriously jaded viewers will resist being sucked into this creepingly scary story of two people stranded in the ocean with only sharks, jellyfish, and each other.
Kentis loosely bases Open Water on at least one actual incident, in which two scuba divers were mistakenly left behind by a tour boat. As played by Blanchard Ryan and Daniel Travis, young marrieds Susan and Daniel have all but forgotten how to seize the day. Before they even pull out of their driveway, Daniel must remind his workaholic spouse "This is supposed to be a vacation." When the Carribean vacation goes horribly awry and the tides pull them out of control, the two experience physical and mental breakdowns as they try not to look like shark bait. Modest currents of dark humor buoy the slim plot, a successor to The Blair Witch Project's horror on the cheap. Susan asks Daniel, "Should we splash? Should we stay still? You're the one who watches 'Shark Week'."
There's not much here, but Open Water capitalizes on its slightness. The heroes are blank slates on which to imprint our own fears of personal disaster, and the slow exposition tells us all we need to know of their delicate personalities. None of their choices, ill-fated or not, seem blatantly unwise in context, the slow momentum of the plot cannot help but become visceral as long as time continues unabated, and the simple ending feels uncompromised. A minimum of scoring from Graeme Revell goes the long way, and the clever editing sells all it needs to sell, letting our imagination do most of the work of putting the actors in sharks' way.
With Open Water, Kentis takes the sting of a scary news report and chills "there but for the grace of God go I" fear into shivers of mortality: better faced with a loved one, but best avoided.