Thanks for the headsup makman94
I didn't know that celestial navigation is not working as it should.
At the moment I'm planning on making coastal maps as slide down charts, the same scale that is shown on the idea picture. I think it might be possible to add the lighthouses to the world maps (the RAW files) with a little bit of cutting and pasting between Sh3MissionEditor and the RAW files, but I have an old laptop that hates doing anything to those huge files, and will have to wait for a new computer to have a go at that.
Anyways this idea is going to be on hold for quite some time, as time is limited.