Don't waste your time, there's barely a plot, no character development and nothing interesting after the first 20 mins. There is a serious lack of anything in this movie, except for serious plotholes... How do the completely blind monsters who dive with complete aggression at any sound suddenly realise they're above water.
I wasn't the slightest invested in the characters and couldn't have cared if they lived or died. None of the questions from the first 2 movies were elaborated on or answered.
They just slapped the franchise name on a totally different movie and hoping to profit off the name.