Luchino Visconti's pseudo-documentary look at the exploitation of Sicilian fishermen was based on Giovanni Verga's 1881 novel I Malavoglia. The townspeople of Aci Trezza, Sicily, portrayed themselves, speaking in their native dialects and fretting about economic hardship for over 160 minutes of screen time.
As nobly neorealist as such an endeavor must have seemed, it died at the box office upon initial release, leading Visconti to add narration in standard Italian.
The truth is that the film wasn't all that realistic to begin with, as Visconti's unshakable attachment to cinematic artifice led him to pretty up the dreary goings-on with camera virtuosity that seems completely misplaced given the events onscreen.
More grueling than illuminating, this film was the first of a proposed trilogy (the remaining films were to deal with Sicilian peasants and miners) that Visconti mercifully never got around to making.