Anyone who's read a few of my previous reviews will undoubtedly be sick of hearing it again, but it's a matter of granite truth: story is everything, even for a movie. If you have a great story, many of the other elements of a movie can be rubbish, and as long as they aren't completely unforgivable, the movie will still be okay. But if you have a crap story, then it's going to be a crap movie and that's the inevitable outcome.
MARY, since it has a crap story (or NO story depending on your perspective), is a crap movie. And that as nice a spin as you can give it.
Almost all of the other elements of MARY are good or excellent. Good production values, some "namebrand" actors, story concept that springs from the incredibly rich tradition of the supernatural so associated with the sea and ships, and so on. It even has a somewhat original/inventive script idea as its basis: a group of people having to deal with a hostile ghost in the isolated and claustrophobic conditions on a small boat.
LOTS of sea-based and boat-based ghost stories abound in horror literature. The Flying Dutchman, an endless stream of ghost and horror stories birthed by the true story of the Mary Celeste (of which I've always been convinced that "Fire in the Galley Stove" by William Outerson was such an example), "The Derelict" by Hodgson, and so on.
You might be tempted to think that there just isn't enough context to write a great story around the sea, a small boat and a handful of people. But we know that's not true; Hemingway did it in "The Old Man and the Sea" and won a Pulitzer Prize doing it. So we know that it CAN be done.
While there are exceptions, I usually include a little preview of the story as part of my reviews, but MARY is one of those exceptions. The story is so shabby and its elements so overused you can summarize the entire thing in two sentences:
There's this female ghost of sketchy origins that haunts a boat christened "Mary". A family buys the boat, refits it, and on its freshly renovated maiden voyage, the family and a couple of friends start trying to kill each other by virtue of the ghost's evil influence and, as you might expect, things end badly. The end.
When you think about it, this really isn't an actual story as such. At best it's THE SHINING with saltwater and with everybody taking turns playing Jack Nicholson. And everybody acting crazy and trying to kill each other for no reason other than ghostly "influence" doesn't really constitute a story in any legitimate sense. It's just people behaving badly at random. With jazz hands.
Personally, I am so thoroughly SICK of the "the devil made me do it" concept I could just throw up when a movie drifts in that direction. The everybody-woke-up-and-it-was-all-a-dream writer's ultimate childish copout would be Pulitzer material in comparison at this point.
It really is a shame. MARY had great bones, as it were, for what could have been an excellent movie. I don't know how, but somebody just forgot to add a story to it.