Ahoy there shipmates, This patch is a first stab at providing support for the 3-byte extended types that are used on marine maps. Extended types are specified as a 6 digit hex number. The first two digits are always 01. An example type is 0x010200 (point type Buoy). Points, lines and polygons can all be given extended types. The cGPSMapper user manual lists all of the types. Note that routable ways cannot have an extended type. If you try to give a road an extended type, it will converted into a line. At this time, the various extra attributes that can be assigned to the marine entities (depth, colour, light colour/flash, etc.) are not handled but I have made some progress in understanding their encoding so at least some of these could be supported in the future. Obviously, the OSM data would need to be enriched to specify the required attributes. It now works well enough to warrant testing on more map data but I am expecting that there will be problems given the extent of the patch and the nature of what it's doing. Please test if you can and report success/failure/etc. Cheers, Mark