A quick guide:
- Make a new map that has a castle sized locations right on the coast (= access to water in the surrouding tiles of the midpoint where the castle icon is)
- Open the map in the map generator, do Tools > Coastal castle fix and save the map again. You can now build harbors to the coast castles.
- Now you need to replace a mission map at DATA\MAPS\MISS_20X.WLD with your .SWD map (200 = first mission, 201 second and so on).
- Edit DATA\MISSIONS\MISS_000X.RTF file (you probably want to remove all !MET events so you don't get weird messages while playing).
- !ENABLE_ALL_HOUSES in the RTF file enables to build all buildings.
- You might also want to add some more people and ware (tools).
Yeah, I know, it is pretty much a hassle and a lot of work and figuring things out. As I already mentioned I'm creating a Campaign Editor that makes all this a lot easier, the target is to make switching to a new campaign a piece of cake and also ease the editing behind a userfriendly interface (no real code to worry about).
If you need the information, I can paste some code from my project that shows what each WARE and PEOPLE are in the RTF files.
Oh, and you can take screenshots. Just press Alt + P and the game takes one. If you'd use DOXBox, you could take screenshots with the regular Print Screen method.