Hello, I am trying to switch to --precomp-sea instead of generating the coastline directly from OSM data. For higher zoomlevels this works fine. For lower zoomlevels (scale in basecamp >=5km) the coastline appears heavily terraced/pixellated. Playing with parameters like poly reduction did not change this behaviour. Here's a screenshot <http://www.wanderreitkarte.de/download/coastline_steps.png> . The real coastline from OSM data is visible as a dotted line. The coastline generated from OSM at the same zoomlevel looks somewhat jagged from polygon reduction, but is not terraced in any way. mkgmap versions: 3366 and 3796 sea file downloaded from mkgmap page <http://osm2.pleiades.uni-wuppertal.de/sea/latest/sea.zip> , 13.2.17 command line: java -jar mkgmap.jar --tdbfile --preserve-element-order --precomp-sea=p:\Input\sea.zip --generate-sea -c osmc_options There are no sea parameters in the option file, poly reduction is at default levels. Any ideas? -- View this message in context: http://gis.19327.n8.nabble.com/Terraced-pixellated-coastline-with-precomp-se... Sent from the Mkgmap Development mailing list archive at Nabble.com.