Trading across the ocean

[Rishara]

How does the game determine if you are connected to a trade network with someone on a continent on the other side of the world? I never noticed it being a problem before, but in my current game, I have circumnavigated the globe (first to do so yay!), have harbors, etc. I'm playing with my better half, and he's on the other continent. He also has harbors, etc in all his coastal cities. We can see eachother's cities on the map, and there is even explored territory between him and myself. Yet, the foreign advisor screen still says he is not connected to my trade network (nor is anyone else on that continent). We also both have free market implemented. We CAN trade tech, just not resources...

What am I missing?

[Solver]

Astronomy gives you a trade connection to places over the ocean.

[Rishara]

Thank you! Yes, that's the problem. Researching it now, so we will soon be happily trading.

[Rishara]

Thank you! Yes, that's the problem. Researching it now, so we will soon be happily trading.