using rivers ?

[Arko]

has someone tried to mod the map to make river provinces navigable as the sea ones ?

 

[jordarkelf]

That'll just cause all armies to have to pay seafaring costs when crossing any river, and make movement speed very slow.

But it should be possible if you change their terrain type to ocean.

 

[Arko]

in some way travelling on long river may be a short for long travels (rhein danube volga...)

when the trip is longer (in time) by sea the army choose the way by land i think