Hakugei Densetsu

Same director telling a story about a crew of pirates led by their manly captain while bearing a thrill of adventure. 

Both are fun, entertaining sci-fi space adventure series with many interesting characters. Made in the 90's. 

Both are space story with melancholic atmosphere. Some characters are similar, and the end make cry. 

Both shows are loosely based off of two classic novels. Nadia being based on "20,000 Leagues Under the Sea" and Hakugei, of course being "Moby Dick". 

Along with the original Space Pirate Captain Harlock (1978) this anime has a similar feel. A quirky, endearing crew centered around a heroic, manly captain. Coming of age stories of young kids. Pirates and spaceships! I also believe Ahab's costume design is based off Harlock or other Leiji designs. There are also similar story elements (best friend is the dead head mechanic, captain becomes the foster father).