Scott Thomas’s review published on Letterboxd:
Pity Underwater, friends, for it is fighting a losing battle from the get-go: it’s built from parts that any person over 30’ is like to recognize; it endears us to its actors more than characters. Which means for many people it’s derivative and thinly sketched at best. That’s a valid take on Underwater.
And: there’s is a 10 year old who’s sneaking into Underwater — who barely knows K Stew or Vincnt Cassell or even Alien — who will quickly get bodied by this movie. Because they’ll focus on its claustrophobic atmosphere. They’ll be retching at some of its kill shots. And they’ll gey gobsmacked for the solid third act, which is anchored to one great sequence. How great? I almost shouted a horror legend’s name out loud while watching it. That’s how great.
Should gateway horror do more? Maybe. But Underwater is a gateway horror film and I, for one, don’t think it has to. It’ll give the genre itch to someone; hell yeah, is that glorious.