A really good film, I found it much better than the average youth film and English social-realism drama. Basically it's a film about youth feeling confined in both the poverty of the English working class and the superficialness of the the upper-class and about love as a possible way out.
The basic problem of the film is that non of the manly main characters are sympathetic even the slightest. They are extremely egocentric and unable to accept the realities of life (on land) and flees to the depth of the ocean without accepting that it's physical impossible for them to live down there, costing lives. In the process they end up destroying their own lives and everyone around them, not even sacrificing a single thought on the consequences for the ones that love them. Basically egocentric pricks and that creates a distance to the main characters that the film can't survive.