[OSM-talk] How to obtain a small coastline polygon for TileMill?

[Steve Bennett]

Hi all,
  I'm learning TileMill with a project to render my home town of
Melbourne, which is on the southeastern coast of Australia. The only
problem I'm having is the coastline. I've tried a few things, and
nothing has really worked:

1) The default 'countries' shape that comes with TileMill
- not enough detail, misaligned with OSM data (maybe the wrong projection)

2) Cloudmade's Victoria coastline
(http://downloads.cloudmade.com/oceania/australia_and_new_zealand/australia/victoria)
- I think it's just a way, not a closed polygon. As a result, applying
a fill to it doesn't really work - bits of water don't get filled, and
bits of land do.

3) Cloudmade's victoria.poly
(http://downloads.cloudmade.com/oceania/australia_and_new_zealand/australia/victoria/victoria.poly)
- not in a format that TileMill recognises.

4) Cloudmade's whole Australia coastline:
http://downloads.cloudmade.com/oceania/australia_and_new_zealand/australia/australia.coastline.osm.bz2
- aligns perfectly, but seems to be broken:
https://dl.dropbox.com/u/767553/broken-coastline.png


5) openstreetmapdata.com's land/sea polygons
(http://openstreetmapdata.com/data/land-polygons)
- very slow to render (because it's the whole world?)
- it's off by ~25km south of the other OSM data. I used the Mercator projection

I'm using TileMill installed on an Ubuntu VM with PostGIS. The OSM
data I'm using came from here:
http://osm-metro-extracts.s3.amazonaws.com/melbourne.osm.pbf

Can someone advise the best way to get a simple coastline polygon into
TileMill? For this project, I really only need a single polygon of
Port Phillip Bay (or alternatively, a single land polygon covering
greater Melbourne).

Sorry for the newbie questions.

Thanks,
Steve