Need Intercontinental Strategy Help

[Numi]

Hey everyone, so I'm in this game now, huge/king/continents, and I'm not really sure what the best course of action is here as I have never been in this situation really.

Its been a long game up till this point, over the course of 3 days so you know I don't want to lose haha. I'm on a big continent that will be all by myself once I conquer Japan which I am doing as we speak. After Japan there are a few more civs left. None of them seem to pose any threat except one, the Iroquois. I am just discovering coal and he already has aluminum.

I know once I finish up with Japan I'm going to have to do something about him, but I am not sure what. I have no experience mounting a large offensive over a huge ocean especially against a technologically superior AI. Anyone have any tips or strategies as to how or when I should do it? Or just any general advice that will help me be more successful.

Thanks in advance.

 

[Bibor]

You didn't mention if diplomatic, cultural or space-race victory options are available to you.

If you're planning an invasion, you need to give more details about Hiawatha's continent (other opponents, (captured) city states, location of his capital. Best post screenshots of the continent after you scout it out (which you should do; sign open borders and get a fast cavalry there)