Access hydrographic data about the features of the seabed around the coast of New Zealand and in selected areas of Antarctica and the South-West Pacific.

When we talk about the work that LINZ does producing hydrographic data and nautical charts, we are referring to data and charts for New Zealand’s area of responsibility – covering the coastal waters around New Zealand and parts of both the Antarctic and the South-West Pacific.

The group within LINZ that does this work is the New Zealand Hydrographic Authority (NZHA).

Data available through the LINZ Data Service

LINZ produces official nautical charts to aid safe navigation in New Zealand waters and in certain areas of Antarctica and the South-West Pacific.

Hydrographic data is available in its raw form through the LINZ Data Service (LDS). This data is based on official Electronic Navigational Charts (ENCs) and the official NZ Mariner Raster Navigational Charts  (RNCs), both published by LINZ. Tide station locations and bathymetric/scanned sounding sheet indexes are also available  through LDS.

Note: Data made available through the LDS does not replace official navigational charts, as it is not updated as regularly as the Notices to Mariners updates. Data from LDS should not be used for navigation. For navigation, mariners should use official New Zealand Charts as available from chart retailers, official ENCs and/or official RNC products.

View Electronic Navigational Charts (ENCs)
View Official Raster Navigational Charts (RNCs)

Chart vector data

ENCs are specifically designed for use in electronic navigational systems onboard ships. The New Zealand Hydrographic Authority is responsible for creating and maintaining the official set of ENCs for New Zealand, South West Pacific and Antarctic waters.

Prior to loading onto the LDS, the S-57 data from these ENCs is converted to shapefile format. It should be noted that due to the translation process, some characteristics of the S-57 data may not convert correctly to shapefile format. This data is updated on a six-monthly basis.

Chart geotiffs

The RNC portfolio is designed for use in conjunction with compatible viewing software: Electronic Charting Systems (ECS) or Electronic Chart Display Information Systems (ECDIS). LINZ publishes NZ Mariner in BSB format as an annual chart base file plus a monthly cumulative chart update file of corrections published in Notices to Mariners. The NZMariner files can be downloaded from the LINZ website free-of-charge.

The BSB files are then used to generate georeferenced geotiffs, for publication on the LDS. This is published alongside an index of charts and their locations on a WGS84 Datum. These images are updated on a six-monthly basis.

Individual georeferenced chart images are available for download from the LDS. If you’re not sure what chart you need, you can first search LINZ's online Chart Catalogue. If you are a regular customer, you can download and visualise the chart index in your GIS system.

You can also embed hydrographic charts into your web, mobile or GIS application using LINZ's map services.

Bathymetric Data Indexes

LINZ is comitted to share its bathymetric data – data about the depth of the ocean floor.

Through the LDS, we’ve shared a collection of indexes that show what bathymetric data we hold. You can use this to assess the suitability of the data for your needs and submit a request for what you need.

These indexes have been compiled from information sourced from LINZ’s hydrographic and bathymetric databases, and georeferenced images. These indexes refer to LINZ’s bathymetric datasets and will be updated as new data is received.

The majority of our bathymetric data is available as georeferenced TIFF images of the original hard copy sounding sheets.

Data collected after 2000 is often available as both georeferenced TIFF images and digital data files. These data files may be available in several forms, including dense point clouds, thinned point clouds, or a 3-dimensional surface model.

Note: The LDS does not hold bathymetric data, instead providing indexes to enable discoverability of bathymetric data; all requests for data must be ordered via

Access bathymetric data indexes

Tide stations

Tide stations are the locations around New Zealand and its waters at which sea level measurements either have been, or continue to be, made. Information about these tide stations and their location can be found on the LDS.

LINZ publishes official tide predictions and sea level information through the annual New Zealand Nautical Almanac. Predictions for tides and tidal streams are also made available in CSV and PDF format from the pages below.

Sea level data for selected tide stations is available for download from the LINZ website.

New Zealand Nautical Almanac
View tide predictions 
Download sea level data
Tide station index 

Marine Geospatial Information

In New Zealand, many organisations, including LINZ, collect and store marine geospatial information (MGI). The LINZ website provides links to New Zealand’s MGI data portals to increase the findability and accessibility of MGI.

Finding and accessing MGI

Last Updated: 4 November 2021