Single Civ Continents

[Crossfire]

Once you start playing on harder difficulties, you can't match the AIs at research. The only way to do well is to beeline and trade techs or make war. In that Noble is pretty boring and easy once you understand the game mechanics, playing without the ability to trade or conquer on challenging levels is a losing proposition.

[TheArsenal]

Although there is a Custom Option that says (something like) “one continent per civ” there is a limit. I’m not sure exactly what the limit is, but I’ve tried that option with 15 to 18 Civs on a Huge Map on various occasions and the generator went ahead and had a few civs share a continent. It was more like 3 medium continents, and lot of small (mostly) uninhabited islands.

I've never tried this with islands.

[khearn]

I've played the Island map with 1 civ per large island with a few extra large islands. I got stuck on one of only three large islands that were "ocean isolated", and the other two were empty. All of the AIs were able to reach at least one other AI with galleys. But it worked out OK, since it spurred me to reach optics and Astronomy much sooner than they did. I was thus the first to circumnavigate the globe, and also was way ahead in colonizing the other two isolated islands. The one non-isolated empty island ended up with cities from four different AI civs on it.

The trick in this sort of game where everyone starts out on seperate landmasses is to make a high priority on reaching Optics early. This allows you to make first contact with other civs, so you can:
a) Trade techs on your terms
b) Spread your religion to the AIs that don't have a religion yet.
c) Circumnavigate the globe first, for the +1 naval movement bonus which will be very useful on this sort of map. There's nothing like having a destroyer with 11 movement (after the 2 navigation promotions). Zoom-zoom!

It's also important to get to Astronomy quickly, so you can set up resource trades before the AIs are trading amoung themselves. This lets you get more resources. If a civ only has two bananas, their spare will go to whoever asks for it first.

The problem (if you consider it a problem) is that the AI doesn't seem to understand the type of map, and doesn't make naval techs a priority, so the human has an "unfair" advantage. This is most extreme on the Terra map, but also shows up on these isolated start maps. I think the AI will start leaning towards naval techs once it determines that it is alone, but the human knows from the very start.
Of course, if you want the AI to be a little bit handicapped, these maps are great for that.