James Cameron's 1989 aquatic epic The Abyss was, quite literally, a watershed in the annals of filmmaking: not only was it the first (and only) movie to be shot almost entirely underwater, in the largest tank ever used for a movie set, and to use live dialogue from specially designed headsets, it also pushed forward the boundaries of computer animation in one gigantic leap. The famous water tentacle sequence is now regarded as the defining moment when CGI came of age; ironically perhaps, its very success has ensured that the punishing realism of the setting, which is the best thing about the movie, is likely never to be attempted again.
But the impressive technical aspects aside, is the movie any good? Granted it contains any number of striking moments, from forcing a rat to breathe liquid (it really works, apparently) to resurrecting a drowned Mary Elizabeth Mastrantonio. But the story is a slim one for the running time, especially in the extended Special Edition version which plays almost half an hour longer than the theatrical cut and contains a completely excised subplot featuring much too much heavy-handed moralising: "How all the world can stop fighting and learn to get along with each other", by James Cameron esq. All you need is love, apparently. Here is one rare example of the theatrical cut being preferable to the director's. Now, if only he had cut the love story from Titanic too