Some of the shark scenes are used more than once throughout most of the film. For example, the beach scene when people are being devoured, has a scene in which sharks are swimming and one shark snaps at the water. This scene appears several times in different areas of the film. Some shark scenes are even shown once then again immediately after it ends.
In the opening scene the divers are wearing Octos, a breathing device that must be inserted into the mouth and make speaking near impossible. However, the divers are able to communicate clearly as though they are wearing radio headsets. On top of that, none of the divers are even wearing any type of listening device just standard wet suit hoods.
The scenes in this movie where surfers are attacked are the same as in Shark Attack 2. You can even see Thorsten Kaye's body up to his shoulders when one of the surfers is being helped by paramedics on the beach.