There’s something truly satisfying about a well-executed B-movie. They’re a rare creature nowadays, typically relegated to streaming services with anaemic budgets and under-qualified actors. That speaks to Underwater’s tricky path to multiplexes; produced by 20^th Century Fox back in 2017 – under the wing of director William Eubank and star Kristen Stewart – it sat on the shelf until its recent release, serving as the final film of 20^th Century Fox under that name. That explains a few things – like the appearance of since-shunned actor T.J. Miller in a supporting comedic role – but also suggests the lack of confidence in pure genre films like this one.

Which is a shame, because our movie theatres would benefit from more films like Underwater. There’s nothing revolutionary on display here, admittedly. Brian Duffield and Adam Cozad’s screenplay has nothing to really distinguish it from reams of post-Alien creature features (especially The Descent, which it closely resembles), other than its late evocation of Lovecraftian mythos. What distinguishes Underwater isn’t its concept, but its execution. Eubank cleverly avoids the self-aware silliness that mars so many similar films, instead favouring a serious approach that prioritises suspense and craft.

As is so often the case with this genre, Underwater is at its best early on, when the tension is high and the true nature of the monsters remains mysterious. Initial scenes centre on an isolated engineer Norah (Stewart), inhabiting a cavernous mining station situated some ten thousand or so leagues beneath the sea. When the station is compromised, her escape through ruined corridors sees her join forces with a handful of survivors, including Captain Lucien (Vincent Cassel), aforementioned comedy relief Paul (Miller) and others who are given enough characterisation to make their inevitable demises sufficiently tragic.

Eubank and cinematographer Bojan Bazelli smartly maintain claustrophobic intensity throughout by positioning the camera at close proximity to their characters. When our protagonist ventures into the ocean – protected by a bulky suit of dubious scientific plausibility – that proximity goes hand-in-hand with obscurity, as the combination of tight, side-on framing and murky waters leaves the ensuing events ambiguous. That might frustrate many viewers, but I loved how it drew us into the clouded, fearful headspace of the characters. (The fact that it disguises the limitations of the effects budget doesn’t hurt, either.)

The screenplay is similarly spare and obfuscatory, focused on how characters will survive each encounter rather than overselling backstory or clichéd characterisation. When it tries to say something – shoehorned environmental commentary, or some of the particulars of the climax – it might stumble, but these moments are thankfully few and far between.

Full credit goes to Stewart for shouldering what could’ve been an undercooked film and giving it real weight. She’s a wisp of a character, solely defined by glancing references to past trauma that might explain her choice to choose such a solitary career, but Stewart’s restrained performance draws us in and evokes a larger life outside the frames of the film. There’s a real physicality to the role too. Granted, she spends in skimpy underwear, but her no-nonsense persona (and a camera that avoids any leering) ensures that it comes across as empowering rather than gratuitous.

Really, I can’t find any major faults in Underwater beyond the inherent limitations of the genre. This isn’t a film tackling big questions or reinventing any wheels; it knows its lane and it sticks to it expertly. If that sounds like your sort of thing, I’d recommend it.