Inverse Mapping

[foremost]

Each participant takes a map that they have done before, but goes back to its initial steps and changes it so that the land and the water swap places. Lakes become islands, continents become oceans, etc...

The maps would be graded based upon two factors:

1) Straight up creatively and skill, as normal, and
2) How well the map complements it's source.

The new map might use the same town names, or, if the cartographer is confident [s]he can pull it off, matching landforms (mountains to underwater trenches, forests to lagoons, etc...). Ideally, the two maps would be presented next to each other for the final WIP, but due to the size limit here, that might not work. Anyway, each cartographer would be required to post clear reference to the source map they were using.

The 'source' map should be one that the cartographer has made themselves.
Additional limits could be applied; for example, no entry can make use of a previous CG Choice map.

I think this challenge would be a good way to see how everyone's skill has evolved and how all of those lovely maps would have turned out differently had the other side of the line been picked.