This series has ancient civilisations (Atlantis), world-wide conspiracies, mysterious captains of submarines, acrobats with lion cubs, and noble villains to be redeemed. The title more closely translates as "Nadia of the Mysterious Seas". Though the series did have the English alternate title of "The Secret of Blue Water".
Of the 39 episodes the first 8 episodes were dubbed and released on VHS by Streamline Video (Carl Macek's company responsible (or is that culpable) for creating Robotech from several other series).
Recently ADV Films have released all the episodes on 10 DVDs with 4 episodes per Disk (apart from the last with only 3). As is common with DVDs these have both an Japanese and English soundtrack.
The names of the DVDs are:
- The Adventure Begins
- The Dark Kingdom
- Aboard the Nautilus
- Battleground
- Nemo's Fortress
- The Deep Blue Sea
- Nadia's Island
- The Secret Cave
- Nadia in Love
- The Prophecy Fulfilled
There is also a Movie sequel. I have now seen this (though I have to occasionally ask myself why). It is weak and spends a lot of time reiterating bits of the series. My suspicion is that it was made on the cheap.
Thanks to s_alanet for the correction