The hydrographic data available through the LINZ Data Service is based on official Electronic Navigational Charts (ENCs) published and maintained by the New Zealand Hydrographic Authority.
Prior to loading onto this service, the S-57 data from these ENCs is converted to a PostgreSQL table.
The following Navigational Purposes and scale-ranges are represented:
1. Overview, 1:1.5mil and smaller
2. General, 1:350k - 1:1,500k
3. Coastal, 1:90k - 1:350k
4. Approach, 1:22k - 1:90k
5. Harbour, 1:4k - 1:22k
6. Berthing, larger than 1:4k
ENCs are not available on LDS.