Something I won’t be saying on my death bed: “I wish I would’ve watched more shows about boats.” Yet another crew of singing seafarers sets off in the Avett Brothers’ uneven “Swept Away,” which opened Tuesday night at the Longacre Theatre. The musical adds a twisted new twist, through — cannibalism.

On Broadway? Not so appetizing. A desperate meal of human flesh definitely does not pair well with the band’s pretty-to-ravishing folk songs from their 2004 album “Mignonette,” named for an 1800s English yacht, the passengers of which succumbed to the grotesque act after their ship sank and several were stranded aboard a lifeboat for three weeks. Before and after they nosh, they sing.

What else? At the show’s start, many years later, we meet Mate, a ripe-looking bearded fellow who is on his own deathbed pondering boats. The tormented man, played by John Gallagher Jr. with a kooky Northeast accent that’s supposedly backwoods Vermont, is traumatized by the harrowing memories of his survival on the unforgiving ocean.

The green-lit ghosts of his three companions implore the weirdo to “fess up!” and finally tell their terrible story. It’s a musical, so naturally he complies. The plot is far from based on a true story, by the way.

The characters don’t have names, and the action has been shifted from a British charter to a still not exactly relatable American whaling expedition. Rarely do I suggest that any show be longer than it already is, but 90 minut.