Last Breath is the latest in an exponentially expanding subgenre of disaster docs in the style of Kevin Macdonald’s Touching the Void, wherein talking heads narrate the tragic or near-tragic events while staged footage partially reconstructs what happened. Acts of bravery, self-sacrifice and sometimes sheer dumb, astonishing luck, as told by brawny men stifling tears tend to be the key components in these movies, and this one is no exception. This time it’s deep-sea divers under (literal) pressure when an exploration of the ocean floor off the coast of Scotland goes wrong, and relative youngster Chris Lemons becomes untethered and must survive with limited oxygen.

To reveal much more would spoil the suspense. This is a workmanlike iteration somewhat ploddingly true to its genre, from the style of lighting used for the interviews, to the sweeping, keening strings-led soundtrack, to the almost shocking moments of humour and honesty. One colleague practically admits he wasn’t all that bothered whether Lemons lived or died since he didn’t know him that well.

The emphasis is very much on the tick-tock of what happened, with titles explaining periodically how many hours have elapsed as the search proceeds for Lemons in the briny dark. No blame gets assigned at any stage – the whole thing is seemingly just the result of poor weather and bad luck, which may make some viewers wonder whether, somewhere along the way, someone made a bad decision. But that’s a question for muckraking documentaries, and this ain’t one of those.