This film is absolutely brilliant. It's viciously uncomfortable in such a way that not only does it keep you on edge the entire time, it also keeps you second guessing yourself. It drags you again and again into situations that more often than not leave you scared and alone over the blackened deep, and it harps on your fear of the unknown nearly constantly. Don't expect jumpscares and your typical horror cliches, instead you should expect a slow burning sense of helpless dread.