There could have been some MultiPolygonRelation errors related to coastlines. I should mention that the checks in JOSM Validator and mkgmap are not overlapping that much. JOSM detects some things better, but it does not detect land-on-land or sea-on-sea situations as well as mkgmap, as it does not "colour" the areas.mkgmap came up with many errors relating to 'anti-islands' - I suspect these are round Scotland, and I'll leave it to local people to sort them out!
This seems possible. On closer inspection, I saw a little flooding on the England/Wales border too.But using Bartosz's coastlines-europe file solved the problem (once I had remembered to reference it before the data files), at the expense of a rather larger gmapsupp file.OK, in that case the issue might be that the Geofabrik cutting polygon is intersecting with some islets that have been added or moved fairly recently.
I think I'll leave this to someone with a bigger computer and more time and expertise. At present, I am not a JOSM or OSMOSIS user.The Europe coastline at http://fabianowski.eu/osm/coastlines/ looks like it could be loaded into JOSM on a computer with enough RAM. It could be an interesting exercise to ask Frederik Ramm for the cutting polygon in *.osm format and load it and the coastlines in JOSM, to see if the Geofabrik polygon can be improved. I did this for Finland a couple of years ago. In addition to the coastline, I observed the country border and a few lakes near the border when I edited the cutting polygon. It took a couple of iterations to get it fully right.
Marko _______________________________________________ mkgmap-dev mailing list mkgmap-dev@lists.mkgmap.org.uk http://www.mkgmap.org.uk/mailman/listinfo/mkgmap-dev