I must have watched a different movie from many of the reviewers. Seems that many of these low-budget 'b' movies get bad reviews for the acting, but I thought the acting here was just as good as it is in most movies. I don't think anyone was 'mailing it in.' As for the movie itself, the plot borrows pretty heavily from Jaws, and the ending (before the credits) is pretty stupid, but the film held my interest throughout. As others have said, there isn't much shark action, and there is no gore, which I found disappointing, but of all the shark movies I've seen, which numbers quite a few, this ranks better than average. And there are even a few moments of intentional comic relief that I chuckled at. Certainly not a must watch, and if you're looking for people being devoured on screen, you'll be disappointed, but there are worse out there.
Review of Bull Shark
