The good, or not as bad, zoomers on the boat trip include Noah (Jack Parr), grizzled Levi’s younger mate and also the ex of good doctor Sam (as in Samantha, and played by Kim Spearman), who’s stuck in the lout party taking the boat out. Is a rapprochement in store? Again, no spoilers. While Levi, having discovered the aforementioned shipwreck, has resolved to report it to the authorities despite it having been his personal passion — “forty years I’ve been looking for her” — finance bro Brett has other ideas, and his money does some persuasive talking. So off Levis and company go to drop the wannabe adventurers in the drink. Where they find skeletons, claustrophobic settings, and eventually a snapped guideline. Did a barracuda do that? No, of course, a barracuda didn’t do it.

The arrival of multiple huge speed-of-light sharks coincides with everyone’s oxygen tanks getting dangerously low. While Levi mostly stays on deck knitting — a “dexterity exercise” to soothe his dive-damaged nerve — his reference early on to his old red scuba suit and the nickname it bestowed on him back in the day stands out like Chekhov’s proverbial first-act gun.

His work as Levi represents the final film appearance of Julian Sands, who died in 2023 while hiking in the San Gabriel Mountains of California, and he’s reliably wry as he first resists heroics and then goes for broke.

The movie’s lifts from “Jaws” are so blatant that they might as well be read as affectionate, aspirational homages. As goofy and unconvincing as it often is, “The Last Breath” is difficult to get exasperated over. It may go down easier still if you opt to see it in a very well-air-conditioned setting.