Land Information New Zealand (LINZ) is beginning work on its New Zealand Bathymetry Investigation.

For additional hydrographic and bathymetric definitions please refer to the IHO hydrographic dictionary

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Accessibility (of data)

The degree to which data is readily obtainable.

Availability (of data)

The degree to which data is suitable or ready for use.


ANZLIC meta data standards

The Australia New Zealand Land Information Council (ANZLIC) Metadata Profile (version 1.1) is the recommended e-GIF geospatial metadata standard for use by New Zealand government agencies. The Profile was endorsed by the State Services Commission in July 2010, following a consultation period which showed support for the Profile from the geospatial community. Local government and Crown research institutes are also encouraged to use the Profile and private industry is free to use it as well.




The line from which the seaward limits of a state's territorial sea and certain other maritime zones of jurisdiction are measured. Normally, a sea baseline follows the low-water line of a coastal state. When the coastline is deeply indented, has fringing islands or is highly unstable, straight baselines may be used.


The determination of ocean depths. The general configuration of SEA FLOOR as determined by profile analysis of depth data.

Bathymetric Survey

Surveys not designed specifically for charting purposes, e.g. coastal mapping, oil companies, cable laying companies, construction, etc.



Contiguous Zone

A zone contiguous to a coastal state's territorial sea, which may not extend beyond 24 nautical miles from the baselines from which the breadth of the territorial sea is measured. The coastal state may exercise certain control in this zone subject to the provisions of International Law.

Contour (or contour line)

A line connecting points of equal elevation or equal depth.


Relates to the proportion of the seafloor that is surveyed in a bathymetric or hydrographic survey. For example, Multi-beam echo sounders can provide a complete and continuous coverage of the seafloor.



Data Currency

Data currency generally refers to whether a dataset is current or up-to-date.

Data Custodian

There are two types of data custodian: Leadership and Delivery
The Leadership Custodian ensures that appropriate management policies and standards are developed and maintained on behalf of the Crown.
The Delivery Custodian has responsibility for the continued existence, availability, and integrity of the dataset for as long as required.

Data Steward

The Steward (an agency) considers a holistic and aspirational view in the national interest across a fundamental data theme. The agency promotes good practice, and coordinates activities to ensure best outcomes, overseeing data architecture, quality, maintenance, metadata, pricing, licensing, access and release. The Steward brings the views of users to the table. Stewards are accountable for maintaining the quality, integrity, availability and security of the data so that it meets the needs of users.


The vertical distance from a given water level to the bottom the water body.

Digital Elevation Model (DEM)

A digital model or 3D representation of a terrain's surface, and includes all objects on it e.g. plants and buildings.

Digital Terrain Model (DTM)

A digital model or 3D representation of a terrain's surface that represents the bare ground surface without any objects like plants and buildings.


The use of any piece of information relates to how discoverable it is, hence discoverable data is data which can be physically found easily. Metadata or information about data can help make data become more discoverable.



Exclusive Economic Zone (EEZ)

The exclusive economic zone is an area, not exceeding 200 nautical miles from the baselines from which the breadth of the territorial sea is measured, subject to a specific legal regime established in the United Nations Convention on the Law of the Sea under which the coastal state has certain rights and jurisdiction.

Extended Continental Shelf

The sea zone that, defined by UNCLOS, extends to the limit of the continental margin, but no less than 200 nautical miles from the baseline.


The geographic domain of a data collection i.e. the geographic area covered by a survey or dataset.



General Bathymetric Chart of the Oceans (GEBCO)

GEBCO consists of an international group of experts who work on the development of a range of bathymetric data sets and data products, including gridded bathymetric data sets, the GEBCO Digital Atlas, the GEBCO world map and the GEBCO Gazetteer of Undersea Feature Names.



Highest Astronomical Tide (HAT)

The highest tidal level which can be predicted to occur under average meteorological conditions and under any combination of astronomical conditions.

Hydrographic data

Hydrographic data is information about the features of the seabed, and is often used for navigation.

Hydrographic Survey

Surveys prepared specifically for nautical charting.



Internal Waters

Waters on the landward side of the baseline of a nation's territorial waters. It includes waterways such as rivers and canals, and the water within small bays.

Intertidal Zone

The intertidal zone (also known as the littoral zone) is generally considered to be between mean high water and mean low water.



Littoral zone

See Intertidal Zone

Lowest Astronomical Tide (LAT)

The lowest tide level which can be predicted to occur under average meteorological conditions and under any combination of astronomical conditions.



Mean high water

The average height of all high waters at a place over a 19-year period.

Mean low water

The average height of all low waters at a place over a 19-year period.



National Oceanic and Atmospheric Administration (NOAA)

NOAA is a scientific agency within the United States Department of Commerce focused on the conditions of the oceans and the atmosphere. In relation to bathymetry and global relief NOAA provides scientific stewardship, products, and services for ocean depth data and derived digital elevation models.

Nautical Chart

A chart specifically designed to meet the requirements of marine navigation, showing [depth/depths]] of water, nature of bottom, elevations, configuration and characteristics of coast, dangers and aids to navigation. May be a paper chart, electronic navigational chart (ENC) or a raster navigational chart (RNC). Also called marine chart, hydrographic chart, or simply chart.

Nautical Mile

A unit of distance that is approximately one minute of arc measured along any meridian, equal to 1,852 metres exactly.



Satellite Derived Bathymetry (SDB)

Bathymetry data derived from satellites, mainly through the use of high resolution imagery and altimeters.



Territorial Sea

A belt of water of a defined breadth but not exceeding 12 nautical miles measured seaward from the territorial sea baseline.

Third Party Data

Data which is not collected directly by your organisation but which is obtained from existing sources.



Usable data

The extent to which a product (such as a device, service, or environment) can be used by specified users to achieve specified goals with effectiveness, efficiency and satisfaction in a specified context of use.

United Nations Convention on the Law of the Sea (UNCLOS)

UNCLOS is an international agreement that defines the rights and responsibilities of nations with respect to their use of the world's oceans, establishing guidelines for businesses, the environment, and the management of marine natural resources.