THEATRE: Dames at Sea, Ambassador's

David Benedict dons his sou'wester and boards the good ship Musical Pastiche

If you've ever seen Dames, 42nd Street, or any of the classic Warner Bros musicals, you can guess the plot of the pastiche musical Dames at Sea. In case there's any doubt, the knowing sidekick is named Joan, as in Blondell, while our heroine is Ruby, as in Keeler, who couldn't sing, couldn't dance, couldn't act, but married well (Al Jolson). I don't know about her marital arrangements, but Joanne Farrell wipes the floor with Keeler in the other departments.Ruby pitches up backstage all the way from Utah and guess what? She's a dancer, wants to be in a Broadway show and is hired on the spot much to the chagrin of monstrous leading lady Mona Kent, the resident Lady Macbeth of 42nd Street. Love interest appears in the shape of two sailors (Jason Gardiner and John Peterson, excellent), one of whom, Dick (as in gut-busting permanent juvenile Dick Powell), just happens to be a song-writer. But the theatre is being demolished, so what are we gonna do? Hey, let's put the show on right here on board ship!

The show is packed with numbers shamelessly ripped off from Hollywood stalwarts. "Singapore Sue" was clearly separated at birth from "Shanghai Lil" of Footlight Parade, while Mona's torchsong "That Mister Man of Mine" is less of a homage than a direct steal from the Gershwins' "The Man I Love" complete with stepwise descending bass. The six-strong cast has the two most important things you need for musicals: bags of energy and good teeth. They've got so much confidence they should be advertising Colgate. John Gardyne doesn't so much direct as organise the traffic, pile on the sight-gags and wait for the next number which, in Act 1, leaves the cast more than a little adrift. Happily, James Hendy's witty set designs and choreographer Lindsay Dolan save the day (you try doing a Busby Berkeley number with six people in spangly yellow plastic macs and sou'westers).

Sara Crowe, with her peek-a-boo squeak of a voice is wildly miscast as the broad, but her timing and tapping win you over. Unsurprisingly, Kim Criswell as Mona wins the singing stakes hands down, vamping, nay, camping, her way through "The Beguine" like a cross between Madeline Kahn and Miss Piggy, although if I were her, I'd sue over her first costume.

Even pastiche needs a touch more truthfulness than it gets here, but face it: how can you not warm to a show with a Tyrolean dirndl number and the climactic line, "You're going out on the poop deck a chorus girl, but you're coming back a star"?

To 8 June. Booking: 0171-836 6111