Swallows and Amazons, Vaudeville Theatre

Four children allowed to go off in a boat on the Lake District by their mother without a responsible adult or lifejackets? If this happened today Social Services would be down on mum like a ton of bricks. But this is 1929, long before the tyranny of parental paranoia, which may go part of the way to explaining why Arthur Ransome's story of childhood adventure, unfettered by adult interference, is such an enduring hit.

The involvement of Hannon inevitably invites comparisons with another recent family-orientated West End opening featuring music by someone not known for their theatre work. Tim Minchin's Matilda and Swallows and Amazons are both great but very different. Compared to Minchin’s full-on score, there is a lightness of touch to Hannon's jaunty compositions, which gently nudge the plot along. Another nice idea is having the musicians take part in the action. One minute they are playing along, the next minute they are playing characters.

Alongside the music it is the main quartet of Walker siblings, Titty, John, Roger and Susan (pictured, l to r, Akiya Henry, Richard Holt, Stewart Wright and Katie Moore) who drive the plot as they sail off in the Swallow and fight the Blackett Sisters before forming an alliance to take on the villainous – well, actually quite benign – houseboat man Flint. The story, scripted by Helen Edmundson, unfolds without bombast, but with some fabulous set-pieces. Birds are conjured up by cloth, with scissors and secateurs for beaks, blue ribbons represents the water and in one fabulous swimming scene Titty brings a whole new meaning to stage diving.

In fact the imagination and inventiveness of designer Robert Innes Hopkins neatly echoes the imagination of the Walker family, who easily convince themselves and the audience that they are on a pirate adventure looking for buried treasure. Dreams and reality blur into one, particularly in one Fantasia-like musical number in which Titty appears to be haunted by dancing treasure chests.

Despite the politeness of Tom Morris' direction and the squeaky-clean behaviour of the Von Trappish protagonists – a policeman berates them and does not get stabbed or even have his helmet knocked off – there is more than enough fun here to keep your average pre-teen boy hooked. The one next to me might have been glued to his phone during the interval but he happily put it away when the drama recommenced.

As the japes build to a climax things do slip into posh panto modeAs the japes build to a climax things do slip into posh panto mode, with plenty of well-behaved audience interaction. There is a further clever touch here though, as the drama literally floats out into the stalls. Do not be fooled by the frivolity though. What seems like a fairly thin, old-fashioned yarn is also an extremely cleverly constructed piece of drama, working on all sorts of levels. Is their escapism a response to the economic depression of the 1920s? Is their triumph over Flint a victory for the bourgoisie?

If there is one niggle, it is that this is an unapologetically middle-class tale. Despite some feral warpaint this is more Lord Snooty than Lord of the Flies. The producers must certainly be hoping that its archetypal Englishness attracts a more diverse demographic than it did for the performance I saw, when it seemed from my seat in the stalls as if there were more black people onstage (one – Titty) than there were in the full house. This could have been an unusual audience, but somehow I doubt it.

• Swallows and Amazons at the Vaudeville Theatre until 14 January