Near the beginning of the British comedy “Fisherman’s Friends,” we’re treated to a choir of fisherman belting out a rendition of the classic sea shanty, “John Karaka.” The crew is singing against a coral sky, and singing well enough to earn a record deal offer from a hot-shot producer. The lads laugh in his face. But then they think it over: Why not sing on the radio and make some money?

Why not, indeed? The film takes its title from a real-life band of Cornish fishermen who made it big. In 2010, Fisherman’s Friends signed a contract with Universal and made a debut album that reached the top ten, an improbable underdog story ripe for uplift. There’s so much potential in director Chris Foggin’s musical. First, there’s the music, legendary shanties that shake the boat and stir the soul (“Drunken Sailor,” “South Australia,” and “Blow the Man Down” will be stuck in your head long after the credits roll). Then there’s a talented cast of British actors, including Daniel Mays, Tuppence Middleton, James Purefoy, and Dave Johns. There’s the post-card setting, on the coast of Cornwall, captured exquisitely by cinematographer Simon Tindall.

But all of this is drowned out by Foggin’s incessant need to tinker with the plot. Instead of centering the narrative on a group of fishermen, the story follows a big-city producer who drives a BMW and drinks lots of coffee. Mays plays Danny, the talent manager at a record company in London. He has a reputation for being a push-over, so when he and his co-workers come across Fisherman’s Friends on a stag weekend in Cornwall, they persuade him to sign the group. “They are the next Beatles,” his boss (Noel Clarke) tells him. Unconvincingly, his friends then ditch him as a prank, leaving him in Cornwall without a ride home. Moments later, his boss calls: “Don’t come back until you sign Fisherman’s Friends.”

What makes Danny’s situation considerably more-dire, however, is that his boss isn’t serious about signing the band. That was a prank, too. Of course, since this is a comedy with a script by Meg Leonard and Nick Moorcoft (of “Finding Your Feet” fame), it seems likely that Danny will, er, land on his feet. British comedies tend to be lighter than American ones, so you never feel like Danny is in any real danger–his obstacles are more speed bumps than roadblocks. By the time he figures out he’s being played, he’s signed the band, won over the village and, no offense to Mays, landed an Airbnb hostess (Tuppence) who is way out of his league. 

“Fisherman’s Friends” is awash in unlikely scenarios and drenched in high-key lighting, for better and worse. This is the kind of movie where a London pub randomly bursts into a full-blown rendition of “Blow the Man Down,” where conversations are accompanied by crowds of smiling extras in the background. There’s dialogue about Davy Jones’ Locker and jokes about “Reservoir Dogs.” Which would be more forgivable, if the film balanced its silliness with seriousness. The Friends deserve more than a corny farce about their agent–they deserve a rich exploration of their history, character, and moral compass.

Fittingly, once the focus shifts to the band, “Fisherman’s Friends” hits the feel-good sweet spot. The band is the reason to see the film. The actors look, act and sound like genuine lads, with chemistry you would expect from a group of friends who have weathered storms both physical and emotional. Their beards may be graying, their skin sagging. But as the cheery final shot proves, nothing, least of all age, can blow these men down. [C]