I'm surprised to see it has been trashed by commenters. It's definitely not a new thing, think about another sea terrors: drowning, unknown creatures, castaway, lack of water and food, impossibility to reach out to the rest of the world and so on. Two movies come to mind, including The Impossible, with Ewan McGregor. The thing is this is not the worse of it's genre, it does create suspense, you can feel the tragity, there are some unexpected plots (even while being a sci-fi movie, assuming you are waiting for the unexpected blablabla). Anyway, my concern at the end was: would I want to survive in such a world? What for, if the sixth massive extintion is here to stay?

I'd totally recommend if you're also kind of thalassophobic.