The sharks are getting smarter. Simultaneously, the facility is hit by a wicked typhoon. The movements sometimes seem too fast to be believed, and the digital animators aren't consistent about the size of the creatures. At one point, a shark will look the size of a dolphin, moments later it looks the size of a 747 fuselage. Director Renny Harlin doesn't telegraph at least two attacks - they're spontaneous, unexpected and shocking.
Many scenes are recognizable from earlier movies.