Slitherine

I may have missed it but I can't find anything relating to width of rivers/coastlines.
Most of us of course, will use the stuff we have, and it will be within "reasonable" parameters.
I can see a problem developing though if those parameters are not clearly and officially defined.

In the reference section under Terrain Description:

Coastline - up to 6MUs in
River - up to 4MUs wide

Aha - thats good. I'll just go off and measure mine!