When you hear that the directors of this hallucinatory oddity spend their days working at the "Sensory Ethnography Lab" at Harvard University, you will know not to expect a cheap exploitation flick featuring impaled co-eds. Sure enough, Leviathan is among the oddest, spookiest, most unsettling entities to make it into cinemas in 2013. Whether it belongs there or not is another question.

The film-makers created their piece by mounting robust waterproof GoPro cameras at various corners of a North American trawler as it heaved its way through hostile waters. The picture begins as it means to continue, with a hugely long shot depicting the hauling in of a mighty net. We never see the crew’s faces. We can’t quite hear what they are saying. For the next 90 minutes we are to be immersed in damp, clutter and confusion.

As a work of "ethnography", Leviathan leaves something to be desired. So muddied are the voices and so universal is the look – tattoos, yellow slicks, broad shoulders – that the fisherman could be from any predominantly Caucasian ethnic group. A non-fishing observer would not be altogether surprised to discover that the ship docked in Donegal or the Shetlands.

The sounds and images are, however, stunning throughout. Marvel as the camera locates a busy sweep of circulating starfish. Rock back at a net bulging with angry, glaring fisheyes. In one poignant moment, an apparently distressed seabird – allowed more attention than all but one of the fishermen – feebly attempts to leap over a wooden slat.

For all the aggressive power of the film, it's hard to escape the notion that we are watching a piece of video art that escaped the gallery and made a lunge for freedom. Leviathan has no real structure. There is no sense of meaningful montage. Crucially, it would play just as well if, rather than watching from beginning to end, the viewer began in the middle and allowed the film to progress through a complete loop.

And yet. By golly it looks good on the big screen. Maybe it does belong there for a spell.