Okay, for starters, I really think this is a cool map. Talk about a unique map, and gameplay!
On to the question...
When dealing with the idea of foreign markets, the rules require a Port to qualify.
I learned this thru experimentation, when I took the Market in Colata, and I own the dock next door. (One of the little islands in the middle.)
Curiously enough, it took an extra turn for me to realize, apparently that market has no value what so ever.
Is that correct? Or am I missing something...