“Open Water 2: Adrift” apparently was written as an original story, but someone decided to turn it into a sequel to the polarizing “Open Water” in order to cash in on its success. I'd say this usually spells failure but it seems like I've been having a fair amount of luck with converted sequels as of late. “Open Water 2” is a flawed movie, but I honestly thought it was startlingly effective. It reminded me that both of these films relied almost exclusively on their emotional impact upon the viewer, so you can't just judge either of them as good or bad. I thought “Open Water 2” was a far more rewarding experience than the first film and it doesn't even have sharks!