★☆☆☆☆

JUST because something was once quite popular does not mean it should be remade and repurposed for a modern audience. No truer is that the case than with Baywatch, a lazily scripted cash-in excuse for a Hollywood comedy.

What there is of a plot follows the statuesque Mitch Buchanan (Dwayne Johnson, stepping into David Hasselhoff’s not inconsiderable trunks), head of an elite group of lifeguards who watch over and protect the bay with everything they have.

One day Mitch finds himself butting heads with a reckless new recruit in the form of disgraced two-time Olympic champion Matt “The Vomit Comet” Brody (a distractingly muscular Zac Efron).

Together they and the rest of the Baywatch team – which includes skilled new recruit Summer (Alexandra Daddario), experienced Baywatchers CJ (Kelly Rohrbach) and Stephanie (Ilfenesh Hadera) and bumbling wannabe lifeguard Ronnie (Jon Bass) - attempt to take down a local drug lord (Bollywood superstar Priyanka Chopra).

That kind of crime action plotting mixed with abrasively adult humour reeks of desperation in trying to recapture the magic of the 21 Jump Street reinvention. But the written-by-committee script – credited to as many as six screenwriters and story creators – is so painfully light on any genuine, well-conceived jokes it almost becomes a feat in itself just how laugh-free the whole thing is.

What passes for humour is a cavalcade of dim-witted penis jokes (to put it politely as the film never would), gross-out vomit gags and a bizarre obsession with Johnson’s beach hero calling Efron’s similarly beefed-up new recruit names like “NSYNC” and “High School Musical”. When it’s not punishing you with its one-note jokes, it’s throwing generic action with hilariously ropey CGI or just plays up to the inherent leery quality of watching people in swimwear running slow-motion without any sense of the irony about it.

Not even the power of The Rock can save this intelligence and funny bone-insulting revamp that’s stupid in all the wrong ways. Yes, we really are indeed in the shallow end of Hollywood comedy here and the water is particularly naff.