Dive, BBC2<br/>Storyville, BBC4

Like you perhaps, I have become so inured to the mannerisms of teen drama – the issue-laden scripts, the fidgety camerawork, the look-at-me performances – that Dominic Savage's Dive came as quite a shock.

Over two hour-long episodes on Thursday and Friday evening, his simple boy-meets-girl tale calmly, insistently, and quite beautifully, set to rights cliché after cliché. Whether the result was much more than a glorified two hours of genre housekeeping, I'm still not quite sure. But Savage wielded his duster with relish.

The plot, for instance, was almost indecently simple: schoolgirl diving prodigy Lindsey (Aisling Loftus) becomes pregnant shortly after beginning a relationship with fellow pupil Rob (Jack O'Connell). From this soapy-sounding premise, the obvious focus was whether Lindsey would still be able to continue pursuing a talent that might take her to the 2012 Olympics. Instead, Savage didn't even bother with a confrontation scene between Lindsey and her coach. The two episodes were billed as, respectively, Lindsey's story and Rob's story, yet this apparently highfalutin device turned out to be no more than slight change of emphasis, with episode two continuing on from the previous evening, with Lindsey and her home life ceding to Rob's.

That hackneyed teen pregnancy then became a cue to examine how a couple of everyday kids such as Lindsey and Rob might react to imminent adulthood, and whether their tender relationship would survive along the way.

And boy, did Savage have ambitions for his and Simon Stephens's modest script. Not a significant moment in their journey passed without a visual metaphor to ram home the point: Rob stomps off from his mates at a path that splits in two directions; a blissful moment of freedom on the beach for the young couple takes place beneath a pair of colourful kites fluttering in the breeze. As for Lindsey's diving, that stood, as far as I could tell, for the fall from childhood grace that every adolescent has to make as artfully as they're able.

Danny Cohen's photography, too, also worked very hard, not to say laboured, to establish Dive's universal themes. As beautifully composed as it admittedly was, you wondered whether his eye was on his human subjects or on that glowering ocean horizon or fetching swimming-pool architecture. And, oh, the bloody cellos – Savage is a skilful enough writer and director to have forgone the wash of mournful strings that drowned out countless passages over the two evenings. Thank goodness for those relatively busy scenes involving Lindsey's mother (Gina McKee) and Rob's father (Eddie Marsan), in which neither the photography nor the score intruded.

But I quibble. There was more than enough room for two wonderfully moving performances from Loftus and O'Connell. The quiet, steely Lindsey can't have spoken more than a few dozen lines of dialogue throughout, but Savage recognised the power of her calm face with its blue eyes; by contrast, Rob came on like a Jack the lad, but, thanks to O'Connell, evolved into a complex figure of young male confusion and compassion.

Storyville: Leaving the Cult provided another salutary lesson in the power of young resolve. It focused on a handful of escapees from a polygamist Mormon cult in Utah, and their attempts to rehabilitate themselves after a childhood in which all were denied any education beyond maths and Bible studies. Worse, the young female members could expect from their early teenage years to be married off and to begin their primary function: to bear children.

Each escapee executed plans to try to spring from the sect their remaining family members (but never, interestingly, their fathers). Along the way, they understandably struggled with their new lives, dabbling in drink and drugs, prompting the film's most bewildering scene in which a well-meaning but misguided foster family summarily tossed his charges out on to the street. Who'd be a teenager, eh? Perhaps it's the hoodies who should be hugging us.