This movie is one sorry mess and its hard to believe it was ever made. There had to be some kind of tax shelter deal that enabled the birth of this monstrosity, because I fail to see how any rational person would ever willingly invest money into a script like this.
The plot involves a government-owned oil rig conducting secretive drilling operations deep underground. Something goes wrong and the crew from a tugboat delivering supplies to the rig investigates. Of course, there are government agents involved and higher-level military officers trying to keep the oil rig experiments a secret from the outside world.
This could have been a decent horror/thriller but the filmmakers obviously didn't care. Some scenes were so blatantly stupid that one would have thought of them as parodies of horror film clichés, but no, they were actual attempts at generating suspense and drama. Usually scenes are included in movies to move the story forward and to develop the characters, but the makers of "Sea Ghost" decided it would better to include scenes that made absolutely no sense in the context of the movie. To top it all off, the CGI was pathetic, I'm sure an eight year old using a Mac could have developed better effects, and would have saved the producers some money to boot. At least the no-name actors tried, although some seemed to be playing it as a comedy and others as a serious horror.