By now we know that Matthew McConaughey’s idea of stretching himself doesn’t extend beyond yoga exercises. Not that we should blame him: if someone offered us a million bucks to show up buffed and tanned in exotic locations and play pin the tail on the donkey with Kate Hudson, we’d grin and bear it too, probably.

The best you can say about Fool’s Gold is that it’s undemanding; a message that everyone involved seems to have taken too much to heart. McConaughey is Finn, a treasure hunter with a credit problem but a long line in charm. Hudson is his soon-to-be ex-wife, Tess – the brains of the operation, apparently – who’s finally figured out that he’s no good for her. Except – wouldn’t you know it? – Finn turns up that lead to shipwrecked Spanish bullion they’ve been looking for all these years and persuades her boss, tycoon Donald Sutherland, to bankroll the operation.

The classic screwball dynamic works best when we sense mutual loathing goes hand in glove with passionate desire. Tess does vouch for Finn’s bedroom skills, but there’s little evidence of either extreme in McConaughey’s lackadaisical clowning or Hudson’s benumbed exasperation. Romancing The Stone this ain’t. Heck, it’s not even Overboard.

A five-minute scene in which Finn and Tess spell out their historical research must count as one of the most soporific exposition sequences in years. It kills a movie that was barely sentient to begin with stone dead.

Alexis Dziena cribs some easy smiles as a bubble-headed Paris Hilton-type celebutante, but whenever it looks like the film might edge into satire director Andy Tennant (Hitch) tacks hard over into sentimentality instead. Bizarre casting lays on a sideshow of phony accents: Ewen Bremner is wasted as a needless Ukrainian sidekick; Sutherland caricatures a genial British toff; Ray Winstone mangles his way through the Florida Keys. Throw in some slapdash slapstick and a dodgy black bad guy (rapper “Bigg Bunny”) and you’re not just mining stereotypes, but close to plumbing the depths…