Hello, I sometimes use the default Mkgmap style, editing some of the resolutions to display at lower zoom levels. I use the following splitter switches. I set the --resolution=12 as the default style has natural=coastline [0x15 resolution 12] java -ea -Xmx2500m -jar splitter.jar --geonames-file=AU.txt --mapid=40000001 --resolution=12 --no-trim --overlap=50000 myaustralia.osm And this for Mkgmap. java -Xms3500m -ea -jar mkgmap.jar --family-name=Mydefault --series-name=MyDefault --style-file=o:\garmin\mkgmap\resources\styles\default --nsis --net --route --remove-short-arcs --drive-on-left --check-roundabouts --make-poi-index --add-pois-to-areas --max-jobs --location-autofill:1 --tdbfile --index --preserve-element-order -c template.args What I have found is that only --overlap=50000 produces perfect maritime borders fully around Australia anything other than 50000, gaps are produced in the maritime borders. I have tried overlap 2000, 6000, 10,000, 15,000, 20,000 30,000, 49,000. Also for other styles I have used, I find --overlap=50000 works the best also. I use the default max nodes as this seems to work fine for me. I tried decreasing the max nodes but then --overlap=50000 is way to high and I then use --overlap=6000 but will have some gaps in the maritime borders. Not too much of a problem as 50000 works perfectly for me, but I was wondering if this maybe a bug. This is what I use in osmosis to produce the MyAustrala.osm file. bin\osmosis.bat -v --rx -b500 enableDateParsing=no file=planet.new.osm.gz --bb top=-6 left=107.1 bottom=-48 right=163.5 completeWays=yes completeRelations=yes --wx -bc500 file=o:\garmin\splitter\myAustralia.osm Regards, Markus_g