Version mkgmap-r3824 was committed by gerd on Tue, 28 Feb 2017 add empty style and use it when reading the precomp-sea data The method SeaGenerator.loadPrecompTile() uses the complex class OsmMapDataSource to read the content of the precomp sea data. This reading needs no style rules but OsmMapDataSource loads the default style for each precomp-sea tile if no style option is given. Using an empty style improves run time a bit. http://www.mkgmap.org.uk/websvn/revision.php?repname=mkgmap&rev=3824