Turning the topsy-turvy of W.S. Gilbert and Arthur Sullivan’s 1878 operetta inside out, this saucy staging of H.M.S. Pinafore is a delight from bowsprit to sternpost.

Pinafore was Gilbert and Sullivan’s first hit and set a template for much of what was to come from that extraordinary artistic partnership. It melds jaunty melodies, acrobatic lyricism and a featherweight story into a comic satire on Victorian society, English Exceptionalism and, in this case, the incompetence of its hierarchy, summed up here in the knob-polisher turned First Lord of the Fleet Sir Joseph Porter.

Director Kate Gaul has pressed a multi-talented cast into the service of a Pinafore reworked for 11 performers and a mutable onstage band anchored by pianist and singer Zara Stanton. Not everyone comes complete with a fully formed set of D’Oyly-Carte-approved vocal pipes but all are versatile comic actors, singers and musicians.

Soprano Katherine Allen does have that set of pipes, by the way, and she deploys them splendidly as Josephine. She has a striking stage presence, too, and her portrayal of this flower of British maidenhood is anything but winsome.

She’s ably partnered by Billie Palin, who gives a boisterous account of Ralph, the jolly Jack Tar of uncertain parentage who has captured her heart, and by Tobias Cole as her father, the upstanding Captain Corcoran.

I can’t imagine the young and chiselled Rory O’Keeffe ever imagined he would be playing Sir Joseph Porter while still in his twenties but his zesty portrayal – one that begins with him stripped to the waist – is a welcome change from the usual doddering and moustache twirling. He even whips out a guitar.

Unusually for this venue of late, all of the music and singing is unamplified, which lends the event a pleasing sense of immediacy and intimacy.

Thomas Campbell manages to bring something of the Widow Twankey to Little Buttercup without obliterating her humanity entirely, and there’s colourful support from an endlessly busy ensemble comprising Gavin Brown, Dominic Lui, Zach Selmes, Sean Luther Hall (a growling, halitosis-stricken Dick Dead Eye), Bobbie-Jean Henning and Jermaine Chau.

Production designer Melanie Liertz’s costuming – ranging from period to contemporary nightclub and drag is first rate. Ash Bee’s choreography exhibits a similar range of styles (from nautical nonsense to bump-and-grind) and is great fun to watch.