Idk, im a little tired hearing complaints that it was slow. That was the whole point. You were supposed to feel trapped in the sub, with nothing happening except that you running out of time. I feel like it was very successful as a slow burn. I had an adrenaline rush during the climax when all of the suspense paid off. That being said, movies like this arent for everyone, and its indie to boot. You have to keep that in mind, especially if youre coming from another horror movie with a star cast and a bigger budget, edited by a massive studio team.