Why was Prince Henry's work so revolutionary?

Question

I would know if I could find the ruddy book that told me.......

Answer 1

g. 1418, Prince Henry of Portugal established a marinners’ school
ga. brought shipbuilders, map makers, instrument makers, and sea captains form all over Europe
to Portugal
gb. Financed expeditions to West Africa
h. 1485, Kind Dom Joao of Portugal said Portugal would open a sea route to India
ha. 1488, Bortolomeu Dias sailed around the Cape of Good Hope
hb. 1497, Vasco da Gama sailed to India
i. countries of Western Europe claimed lands discovered by their explorers
ia. Set up colonies
j. 15th & 16th centuries Portugal became a wealthy nation because of its resource rich colonies
k. 1469, Queen Isabella of Castille and King Ferdinand of Aragon were married uniting Spain
ka. Defeated Muslims in Spain in 1492
l. competition with Portugal and desire to spread Christianity led to exploration

Answer 2

Henry the navigator? He made navigation more exacting, before that they were just guessing where they were when a ship was at sea. He took the tales and separated fact from fancy and made a repeatable method to it. Before an old salt took some younger seaman under his wing so to speak and helped the young one get the feel of how things seem. Before it was like watching an old cook who knew what went into the dish but never had a recipe but sort of rememberd the rough proportions. Henry started codifying things, a sort of standards management for ship travel. That and he had the resources and desire to explore when it was still a pretty gutsy thing to go sailing too far afield of places you know.