How bad is it? It's a typical SyFy shark movie (not good).
Should you see it? If it's shark week, it might be one of the better choices, otherwise, no.
This is a case of a great title and premise. A great white shark is killed and then seeks revenge as a ghost and now it can attack from any water source. How can it be stopped? Well, the town of course has a legend that involves the magical cave from which the shark got its powers... Oh, who cares? People get eaten by sharks with ridiculous CGI effects. Richard Moll plays the town drunk.