As always, any film involving time-travel is on thin ice, plotwise, but I'm giving this one a cautious thumbs-up - at least, pending a second viewing, to see if its apparent coherence is genuine. Single mother Jess (George) gets a rare break from her autistic son, on a day's sailing out from Miami with friends, including the boat-owner Greg (Dorman), a trouble teenager he's mentoring (Hemsworth) and Sally (Carpani). A weird electrical storm capsizes their yacht, but sanctuary presents itself in the shape of a passing cruise liner, and the survivors climb aboard. Despite seeing someone on deck as they approached, the boat appears deserted, and seems to be from another era entirely. The weirdness accelerates, as they find a set of keys, which Jess identifies as her own, and a message written on a mirror in blood. It's not longer after, that someone starts trying to pick them off with a shotgun.
Much like Memento, it's a film where you have to sit through the entire running time, in the earnest belief that it will all tie together at the end; if you expect this to make sense from the start, you'll drown quicker than some of the characters. I'm inclined to think it succeeds eventually, as we couldn't immediately come up with any glaring plot-holes, beyond the usual ones of time paradoxes. What it isn't, is particularly horrifying, despite being billed as a horror movie. It's more an intellectual puzzle, and that makes it difficult to invest, because you're never certain what's happening. Even once the basic concept becomes clear, there's enough ambiguity, you're left sitting on the emotional sidelines, holding Jess's coat. Is she "good", "bad" or simply chronologically-challenged? Even after it's all over, I'm not sure, since there's evidence for all three. Credit Smith, who also wrote the script, for keeping his balls in the air [ah... if you see what I mean...] and creating a solid brain-teaser that certainly gives the illusion of working. A second viewing to decide for certain would be more a pleasure than a chore.