Webscroll all the way down to see a short guide on how to get the astronomy skill and where to find the discoveries.
Next are discovery skills that you need to make the actual.
How much faith he has in the captain.
Improves after he sinks ships or defeats their crews.
How strong he is in battle.
Webfor uncharted waters on the super nintendo, gamefaqs has 4 guides and walkthroughs.