A large cove of water with one edge of the water touching one corner of the map. Similar to Meditereanean or Baltic, but with the water extending to one corner. This creates an interesting setup where some of the players will have great access to the sea and a large amount of fishing, while other players will have better access to land and mining resources. It works best in a team game. In order to march an army, you must go around the cove, or you could use transports to move across the cove. And of course, there's some eye candy.
I wanted to see if I could make the water behave consistantly the way I wanted it to, and it came out pretty well by the use of the border constraint commands. I found that the upper left border of the map is always considered the "top_border", even though the RMSG.doc guide says it is chosen randomly. If you look at the script, you can see that I put my own random commands there to make the cove come from different sides of the map.