Triangle (Christopher Smith, 2009)

Some films are so dependent on their plot contortions that an effective representation in a review becomes impossible, for fear of violating the spoiler rule. The evaluation is then simply a thumbs-up or down.
Triangle may start in standard supernatural slasher territory, with a bunch of blandly good-looking friends coming across a ghost ship on a boating trip. The ship of course turns out not to be deserted, and the heroine, played by the instantly forgettable Melissa George, gets trapped in a personal hell.
That the film then turns into a rather blatant rip-off of 2007's Spanish psychological thriller Timecrimes actually turns out to be its salvation. At least it guarantees rewards in terms of piecing it all together.

6/10