The music was awful...
Obviously most of the paltry budget went to Stan Winston's 'creature'... too bad... they weren't able to create 'good underwater sequences' or a 'decent score' for the film.
The score is a huge problem... it lacks any emotion, when you want the audience to be frightened... you play 'tense' music!!... but this score was so cheap and boring.
Sound is very important in film... this is one of the worst 'scores' in a horror film that I have ever witnessed.