I see the same problem as before, even after all these ideas. Any and all ships seem as though they are an afterthought, we need ships, harbors, and trade routes, imbeded into the game. Think thoughout history and even today 60% of the world's population live on the coasts today, now think in a real life sense what would happen if those oceans werent there, just dead open plains, we would be dead, no food transported, no luxuries transported, and so on. So we need to have ships be part of the earliest techs, wether it be fishing ships, small raiders, everything. Up until the mid modern age your people should be nearly completely dependant on oceans, seas, rivers, lakes if nothing else. To point out how valueable they have been in real life, think of countries that have no coastal borders, Kazahestan or one of the many eastern european countries, thoughout history you never hear of great accomplishments coming from such countries, but nearly every country with a coast has had some great and important contrabutions to culture, trade, or military expasion. Without a coast however no countries could make such an impact.