A positive backwash!
Of all attemptable variations likely to stir up a now numb franchise a studio could come up with, we end up with a summer themed classic turned into a Christmas horror tale. Ellen Brody returns and brings back some of the original essence with her tragic presence. The pretexts used for her re-insertion are easy, but it allows us to return to simplicity and some of what we loved initially.
Substituting time spent on a boat for time spent on a plane and traveling from one island to another is enough to feed the eye through what would otherwise feel like filler. The script hinders a potentially better film, sadly. The cast seems on board despite a ridiculous spin on the killer shark: it is either now psychically link to the Brody’s or this is a pointless movie about a crazy woman!
Because the latter is unlikely, the audience will presume the shark is now in supernatural slasher mode, which is nothing new to horror franchises. The fish doesn't always look real, nor does it answer to conventional physics. The main protagonist is a stagnant plot hole and only the shadow of herself. This is arguably one of the most entertaining sequels but it is the dumbest.