Sailing

Requirements
Sailing costs 52 science

2 Science: 26 turns until complete

3: 18

4: 13

5: 11

6: 9

7: 8

8: 7

9-10: 6

11-12: 5

13-17: 4

Leads to
Sailing leads to Calendar and Shipbuilding. That means it can go to maritime, scientific (and even religious) technologies in the future!

Unlocks
Sailing unlocks the Harbor (Royal Navy Dockyard for England), which helps with economy and helps way more with maritime! It unlocks the small wonder National Fishery, which can also be pretty good. It allows the Galley or the Viking longship, and some special abilities. It allows another trade route, which, speaking of, allows trade routes over coast tiles. It also allows builders and traders to embark, so the builders can build fishing boats.