> > noticed that the maps produced by mkgmap are "base maps" whereas
> > Garmin's own maps are "detail maps". Similarly with the
> > "background=water" vs "background=land" (0x10) which ImgTool also reveals.
>
> I don't know anything about this one. It sounds like it might be
> important though.

yes, if these flags can be used to avoid saving land and water polygons I guess it could save some space and time.

Gerd