Gripping, intriguing, and well-paced, Mary overcomes most of the issues with its overwritten script to emerge as a serviceable entry in the genre’s canon. Sure, the film lists from time to time, but it always manages to right itself when it matters.

When it comes to waterborne movies, Wolfgang Petersen’s "The Perfect Storm" (not a horror film) is more terrifying than Mary.

The idea of this boat as a last-ditch play to save a marriage is fine as an inciting incident, but it ends up steering the story way too much. Oldman and Mortimer play the drama in “Mary” well. Too bad they don’t get much chance to play the horror.

With the filmmakers unwilling to explore a kinky, psychosexual bond between a man and his demonic lady ghost-boat, Mary comes to feel as if lacks a through line, collapsing into a series of disconnected horror-movie beats.

Michael Goi, serving as both director and director of photography, does a better job placing the camera around the claustrophobic location than he does exploring the depths of his actors.