The story in this movie is mainly about people and social reactions as situations and stress levels in a closed environment change...what do you think will happen in a movie about a deep-ocean oil rig? Mary Elizabeth Mastrantonio and Micheal Biehn are standouts in this Academy Award winner. (One Oscar out of four nominations...)
Admittedly the Abyss gets a little corny near the end, but hey, this was 1989 remember? This is sci-fi that the wife and hubby can enjoy together.
Sit back and enjoy the screen candy, and realize that this was before everyone just chucked in CG any old time they felt like. Most of the effects in this movie are real-life! (But don't take my word for it, buy this and watch the commentary after you've watched the movie. If all commentaries were this informative we'd have it made.)
A great movie with a great plot, great directing, and great acting. What more is needed?