Building naval bays for Sarmatia

I'm playing a sarmatian campaign and I currently control Asodat. My overall goal is to (somehow) make it all the way to Britain. But so far, I can only build ships in the Crimean.

So my question is, how can I mod in the ability to build a naval bay in Asodat?

Nobody can build naval bays in Asodat.
To get them there, you have to give a hidden resource to the town in the descr_regions.txt and delete the map.rwm (though remember that the trivial script will always place a map.rwm that will revert any changes you make...)