"The Shallows" seems to be an attempt to forge a marriage between critic friendly drama ("Open Water"?) and plebeian friendly entertainment ("Shark Night"?), although the relationship ends up being somewhat turbulent, if passionate.
"Bait" gave me some awesome stuff to chew on: The creative premise, excellent set design, good animatronic shark effects, effective suspense and grotesque violence. But I had to spit out some unsavory seeds, such as crappy character writing, melodramatic drama, inconsistent CGI and a bi-polar tone.