Originally, after Bud has been rescued by the NTIs, they deem humanity a threat, and send enormous tidal waves to every coast on the planet in order to wipe out mankind (although Bud's sacrifice makes them finally change their mind). The effect was initially realized as a plastic wave by Industrial Light & Magic (ILM) that had not been finished when the film was screened for a test audience, so they only saw drawings of the scene. The scene got polarizing reactions (people listed it either as their favorite or least favorite), and James Cameron himself felt that it almost belonged in a different movie. Since the movie was too long anyway, the scene was deleted from the theatrical version. However, years later, Cameron regretted the decision, so he went back to ILM (who had created the water tentacle scene as well as the T-1000 in Terminator 2: Judgment Day (1991)) to finish the wave with computer-generated special effects, and re-instated the scene into the 1992 Special Edition. The lesson he learned from this was to "never, ever preview a movie with unfinished effects".