navigator vs explorer

navigator and explorer both are nouns.

Word	Noun	Adjective	Verb	Adverb
navigator	Yes	No	No	No
explorer	Yes	No	No	No

As nouns, explorer is a hypernym of navigator; that is, explorer is a word with a broader meaning than navigator:

navigator: in earlier times, a person who explored by ship
explorer: someone who travels into little known regions (especially for some scientific purpose)

Other hypernyms of navigator include adventurer.

navigator (noun)	explorer (noun)
in earlier times, a person who explored by ship	someone who travels into little known regions (especially for some scientific purpose)
the member of an aircrew who is responsible for the aircraft's course
the ship's officer in charge of navigation