On Tue, 2011-03-22 at 10:45 +1300, Robin Paulson wrote: > the question becomes (in my mind): why do we have a single way mapped > 'coastline'? this implies the boundary between land and water is > static, but of course it moves - a number of times per day.
The coastline is (as generally accepted on most maps) the mean high tide mark. There is no clear boundary for 'high tide' and 'low tide', since as you point out it moves, and depending on the tide height it may well vary dramatically from day-to-day. If you add say 50cm to a tide height, you might find the tide line may come inland 100m or more. > i like the possibility of a high water mark and a low water mark, used > together to entirely replace the natural=coastline tag. There is a proposal for marking high/low tide marks. Check out http://wiki.openstreetmap.org/wiki/Proposed_features/Water_cover > perhaps some of you have some ideas around this also? You could add a layer tag possibly, and maybe even opening_hours or some other access type tag. David _______________________________________________ talk mailing list talk@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk
