Download Yap map in S-57 ENC format
A map built from OpenStreetMap data, ready to download
Customize the map
Open this place's area in the constructor and adjust everything to your needs
Open in constructor →Map passport
What this map contains by default
This is how the map is built as-is — every setting can be changed in the constructor.
About S-57 ENC
Map of Yap in S-57 ENC — an export of real OpenStreetMap data for the selected area.
S-57 is the International Hydrographic Organization (IHO) standard for Electronic Navigational Charts (ENC): a binary ISO/IEC 8211 file whose defining content is a bathymetric object catalogue (DEPARE depth areas, SOUNDG soundings, DEPCNT contours) plus the full S-57 object/attribute model, mandatory for ECDIS under the SOLAS Convention. A valid ENC cell cannot be assembled from OpenStreetMap: OSM is land-based and carries no bathymetry and no S-57 attribute model. When the GDAL path failed, the previous exporter silently wrote a JSON envelope under a .000 extension — a file that pretends to be binary ISO 8211 but is rejected by OpenCPN, ECDIS and QGIS. We removed that fake: the API returns HTTP 501 on /api/render instead of a bogus chart. Use GeoJSON, GeoPackage or KML meanwhile — they carry the coastline and land geometry honestly. Real S-57 support (bathymetry + S-57 object catalogue via the GDAL S57 driver) is planned.
Which layers are in the file
This file for the selected area contains:
- Roads
- Water
- Greenery
Coordinate systems
WGS 84 (EPSG:4326), selectable in the wizard
Units
Meters (projected in the chosen coordinate system)
| Category | GIS |
| File extension | .000 |
| Tier | Open Beta |
How to use S-57 ENC for Yap
- GeoJSON or GeoPackage — download the shore, the quays and the coastal objects in these formats: they open in QGIS, are read by GDAL/OGR and load into a database with one command.
- KML — if you need a quick look at the area in Google Earth or an auxiliary layer in a program that can read KML.
- Real navigational charts should be obtained from a hydrographic office: they are issued officially and updated through notices to mariners.
Programs that open S-57 ENC
FAQ: S-57 ENC for Yap
Why is it not working?
A valid ENC cell requires bathymetry and the S-57 object catalogue, which OpenStreetMap does not carry. The former 'export' returned JSON under a .000 name — not valid S-57, rejected by OpenCPN and QGIS. We removed the fake. Use GeoJSON, GeoPackage or KML meanwhile.
What comes back if I request the export anyway?
An error with an explanation that the format is not available yet. No file is created: we make a point of not handing out a file that is not a valid S-57 chart.
What should I take instead of S-57?
GeoJSON, GeoPackage or KML: they carry all the land and coastal geometry from OSM — the shoreline, quays, moles, lighthouses. For navigation that is no good, for analysis and illustrations it is perfectly fine.
Will real S-57 appear?
It is in the plans. Two missing pieces are needed for that: a source of bathymetry (depths, soundings, depth contours) and a full catalogue of S-57 objects and attributes. A draft mapping of OSM layers to marine chart object classes is already in the code.
