The Valley of Dinicthys
Marie and Nadia become sick from a dangerously fatal tropical fever. To save them from death, Nemo charts course for an underground reef, where he takes Jean, Sanson, and Hanson on a quest to find the cure. Coming back, however, they have to deal with a territorial, eel-like Dinicthys....
Aired 20/07/1990EP 14 - The Valley of Dinicthys
Nadia: The Secret of Blue Water
In 1889, the world is on the pinnacle of great discoveries in technology. In mankind's grasp for the future, a sinister foe known only as Gargoyle, obsessed with restoring the former Atlantean empire to the glory it once held, begins his plans to take over the world. Nadia, with the help of a young inventor, Jean Raltique, and the mysterious captain Nemo of the submarine Nautilus, must fight to save the world from Gargoyle and Neo-Atlantis. Based on the Novel '20,000 Leagues Under the Sea' by Jules Verne.
(Source: Anime News Network)