I have explored the entire other continent,...all fog of war (not sure if that is what you call it) is lifted and all other civs have been exposed/met. I have probably sent over 40+ missionaries to convert them to my religion as well, so they too have exposed all the land. I have knights and musketmen over there now occupying land, and again I am consistently sending over missionaries so they have no problem accessing the land. There are many different parts of the continent that I am accessing the land as well, not just one spot. Some have coastal cities, but not sure if they all do, but some civs do. Again, I do not know if any of them have established harbours. As for the distance, I believe the only other continent on the map is certainly w/in 30 tiles. it's the ONLY other land mass on the map, I would think I would be able to trade with them. I guess I'll just keep playing the game and see if the trading opens up. I'd hope it would, this is restricting me from generating larger amounts of gold.