Producers: Mark Lane, James Harris, Leonora Darby, Sarah Gabriel and Marc Goldberg   Director: Kate Cox   Screenplay: David Beton   Cast: Ella-Rae Smith, Matthew Daddario, Jessica Alexander, Nikkita Chadha, Jack Morris and Andrew Steele   Distributor: Lionsgate

Grade: C-

If “Into the Deep” weren’t mostly set on a yacht somewhere in the ocean, Kate Cox’s second feature might conceivably have been a one-set play.  Many of the vistas shot by cinematographer Ian Forbes on deck are sweeping, but most of the action occurs below, and is intensely claustrophobic.

To be sure, after one of those openings that point ahead to a future sequence (a woman struggling in the ocean), there are some introductory shots at the unspecified seaside town where, after having a disagreement with her father (Andrew Steele) over his decision to move on from grief over her mother’s death (she’d drowned eleven years earlier), Jess (Ella-Rae Smith) goes off to the harbor, where her friend Emi (Nikkita Chadha) works in a dress shop.  On the boardwalk she meets—cute, of course—Ben (Matthew Daddario), a handsome, charming American, and invites him to a party on the beach that night.

Unhappily there’s an altercation there with a drunken young man (Jack Morris) who seems possessive about Jess, and she accompanies Ben back to his boat, where she falls asleep after a few drinks.  When she awakens the next morning, the yacht is far out to sea, and while Ben promises to get her back to port, there are some troubles with the engine and sails.  They also delay long enough to swim to a nearby uninhabited island.

Finally they prepare to depart, but it’s not long before a jet-ski bumps into the hull, with an unconscious young woman named Lexie (Jessica Alexander) on it.  Jess and Ben bring her aboard and tend to her as best they can, and gradually she revives.

At first the three, fueled by drink and drugs, seem to be having a reasonably good time together, but gradually the mood turns sour.  Lexie begins to recall that she’s met Ben before, and not under happy circumstances.  She warns Jess that he’s a dangerous liar; Ben argues that, to the contrary, Lexie must be crazy.  Before long violence breaks out, and Jess is caught between the two, unsure of whom to believe.  The battle that results is a see-saw affair, with Jess eventually compelled to make a decision and take a stand. 

“Into the Deep” tries to screw up the tension relentlessly, but David Beton’s script too often rambles and stutters, and the editing by Tommy Boulding and Marnie Hollande sometimes allows the rhythm to flag.  And when it comes down to it, Cox opts for an ending that, like so many nowadays, provides the audience with a sigh of relief, however implausible.  Something darker and more cynical would have worked better. 

Smith makes an engaging, if naïve, lead, while Daddario is silkily effective and Alexander intense.  But they’re let down by a script that promises a degree of cleverness it doesn’t possess and of tension it doesn’t muster.