“The Requin” (*1/2 out of four) was a boring suspense thriller about a couple (Alicia Silverstone and James Tupper) on a romantic getaway when a tropical storm destroys their villa and leaves them lost at sea while a ravenous shark swims around and puts them in even more bloody jeopardy. Umpteenth killer shark movie is more-or-less a remake of “Open Water” and is cheaply done and plodding. Silverstone proves she can scream with the best of them but this role isn’t quite the comeback she is looking for.