Other forms: navigators
A navigator is the person whose job it is to steer the ship. The navigator plans and charts the course and then points the boat in the right direction.
Use the noun navigator when you talk about someone who's in charge of planning a ship's route. Airplanes have navigators too, to direct the course they will take using maps and various instruments. A more old fashioned meaning of navigator is an ocean explorer. In fact, in Latin, navigator simply means "sailor," from navis, "ship," and agere, "drive."