Standards and technical specifications for our chart and hydrographic work

Our contractors need to follow standards and specifications when carrying out hydrographic surveys or producing nautical charts and publications. You can read these hydrographic standards and technical specifications and view the International Hydrographic Organization (IHO) resources here.


Hydrographic surveys carried out for LINZ follow a national standard and specification, known as HYSPEC. Originally developed in 1999 and based on the IHO S-44 Standard for Hydrographic Surveys, the 2020 edition of HYSPEC reflects changes in technologies and processes to future proof our specifications and lead good practice.


International standards

International standards that apply to our work are available from the International Hydrographic Organisation (IHO).

2020 Good Practice Guidelines for Hydrographic Surveys

Land information and Maritime New Zealand published the 2020 Good Practice Guidelines for Hydrographic Surveys in New Zealand Ports and Harbours on 19 May 2020. This replaces guidance published in 2004.

The revised guideline provides advice on good practice in the commissioning, standards, and delivery of hydrographic surveys in ports and harbours. It outlines the roles and obligations on agencies in the collection, accuracy, storage, and sharing of hydrographic information.

Read the 2020 Good Practice Guidelines for Hydrographic Surveys in New Zealand Ports and Harbours on Maritime New Zealand’s website.

Interpreting ENCs

Refer to the following catalogues for interpreting objects and attributes of Electronic Navigational Charts (ENCs), which are available from the International Hydrographic Organisation (IHO):

Specifications for contractors

Download the LINZ Source Data Specification (PDF 3MB) PDF | 3.07 MB

IHO Manual of Hydrography

The IHO publication C-13 Manual on Hydrography is another source of information on hydrography, the science of mapping the sea floor, as well as a guide on carrying out hydrographic surveys. It is also a tool for teachers and students involved in hydrographic courses or programmes.

IHO capacity building publications

Last Updated: 2 July 2020