Blake Lively is basically a one woman show in this aptly named survival thriller. The film is paper thin. It's stranded surfer vs. tenacious shark for 87 minutes.
After a stretched out set up, surfer Nancy begins to enjoy the waves on a secluded beach in Mexico (actually Australia). With only two other surfers around, it seems like an idyllic spot. Pretty soon, the dead carcass of a whale floats into view along with the shark that killed it. Things go downhill from there until Nancy finds herself only 200 yards from shore, wounded on a rock outcrop that is slowly disappearing under the rising tide.
Ms. Lively is a very attractive actress who does an admirable job of struggling mightily against the shark and the elements. The scenery is beautiful, the shark realistic, and the tension palatable. It tries hard to be "Jaws" for a new generation but it's a one trick pony...er shark.