Despite having Captain Nemo and the Nautilus, this does not appear to be a sequel or prequel to "Twenty Thousand Leagues Under the Sea". Instead, it takes a few story elements and weaves an all-new tale--one where Nemo seems like a pretty cool guy and all the people from the Earth's surface are total jerks! Talk about role reversals!
The film begins during the US Civil War. A ship from America to England is foundering in a storm. Eventually, when it sinks, six of the passengers are rescued by a passing submarine--Nemo and his Nautilus. At first Nemo is very brusque and gloomy, but soon he warms up to the passengers--announcing they are on their way to Nemo's underwater paradise. And the place IS terrific--like Heaven on Earth. Yet despite the people being kind and the city being paradise, most of the rescued people behave like boorish jerks. Two only see ways to exploit the city and cannot appreciate anything of its beauty. One is an angry claustrophobe who tries to destroy the city simply because he will not be allowed to return home since Nemo wants to keep the city a secret. Another is a Senator who is on a diplomatic mission and he insists on completing his mission--even though his country is in the middle of annihilating itself. And the final two are a mother and child who don't seem like total jerks! There is quite a bit to like about this fantasy film. I much prefer seeing a kinder, gentler Nemo and his hopeful vision for the future. Plus for 1969, the special effects and underwater scenes are pretty nice (aside from the silly monster). And, the story and acting are pretty good. My biggest complaint about the film are the characters from the surface. While it is hard to believe that they would not love this wonderful kingdom, the fact that they seem so unreal--like caricatures--that bothered me. Again and again, they were offered kindness and friendship yet they acted horribly--and for little discernible reason. Greed alone did not explain all this, though the film does amply illustrate that humans suck. I which these people had been more complex--it might have made the film a lot more enjoyable. However, despite this, the movie is a nice adventure--well worth seeing.
By the way, at one point in the film, Nemo tells the guests that they are 10,000 leagues under the surface. Judging by the types of fish you see and the few scenes where you can see light from the surface, the city (if it were real) is about 100 feet or less from the surface.
