As a premise, this backwoods version of the Dead Calm storyline had promise.

However, director Eric Red's inability to render a convincing hurricane leads to a deluge of continuity and lighting errors.

Ultimately, the viewer is more spellbound by the bizarre weather effects than the intended storyline. Intermittent spates of ham-fisted over-direction are similarly distracting.

Charles Dance, doing an 'inbred backwoods hardass' schtick, does his best to save the movie. But ultimately, Undertow squeals like a pig ... and has more ham to boot.