PHerison
(P Herison)
8
We are still talking about the map rendered by Mapnik? Coastlines in Mapnik are handled different than other ways. AFAIR the costlines in Mapnik are updated only once a month. Your edits already appear on Osmarender.
[Edit]: But Osmarender seems to be unable to determin which side of the coastline is land and which is water. I opened a ticket for this: http://trac.openstreetmap.org/ticket/2914