So, Lezales asked me how I got the coast effects in my current WIP thread, A Political Map Korachan and its environs following the Events of the Great War...WIP (yes, long name, it’s a period thing!) so I thought I’d work up a quick wip for this.
1) Use a white base map. On a new layer on top draw the coastline in a hard black pencil tool. The land part was filled in with black to create a good contrast
2) Select the land and create a new layer (called land) and fill the selection white. Add an outer glow layer style, with the following settings, using a nice blue colour. Add a stroke layer style with the following settings using the same blue.
3) add a new layer and fill it with a striped pattern and add a layer mask, hiding the land area.
4) You’re done!
obviously you can tinker with the outer glow settings to get somthing more to your liking, as well as rasterising the wave lines and blurring and/or distorting them