Due to popular demand, we published a detailed guide regarding Map
Creation with proper coastline support:
https://github.com/mapsforge/mapsforge/blob/master/docs/MapCreation.md
The process consists mainly of the following steps:
- Land polygons extraction
- Sea rectangle creation
- Merge with real osm data
- Map building with writer
- Render theme rules
Please inform us if you have any questions about the procedure.