International Hydrographic Organization

The International Hydrographic Organization is an intergovernmental body responsible for coordinating global hydrography and promoting the consistent surveying and charting of the world’s oceans, seas and navigable waters. Comprising over one hundred member states, it develops internationally recognised standards and provides capacity-building support to ensure maritime safety and the effective management of marine environments. It holds observer status at the United Nations and is acknowledged as the competent authority for hydrographic surveying and nautical charting.

Historical Development

The origins of modern hydrographic cooperation lie in the nineteenth century, when maritime nations established national hydrographic offices to produce charts and navigational publications for naval and merchant fleets. Differences in national procedures resulted in inconsistencies that hampered international navigation. The need for harmonisation was raised at several international maritime meetings between 1889 and 1912.
In 1919 Great Britain and France initiated efforts to convene an international conference of hydrographers. Delegates from twenty-four nations met in London to discuss consistent charting methods, the standardisation of hydrographic publications and the establishment of an information-exchange system. The conference resulted in the creation of a permanent organisation whose activities began in 1921 under the name International Hydrographic Bureau. Monaco was chosen as its headquarters following an offer from Prince Albert I to host the organisation.
The first president was Vice Admiral Sir John Parry of the United Kingdom. In 1970 the organisation adopted the name International Hydrographic Organization under a revised convention agreed by its member states. The term International Hydrographic Bureau continued to be used for the secretariat until 2016, when amendments to the convention restructured the organisation’s governance. The secretariat is now led by a Secretary-General supported by two Directors.

Structure and Governance

The organisation is governed by an Assembly, composed of representatives of all member states, which meets at regular intervals to set policy and elect senior officials. A Council consisting of a selected group of member states meets annually to oversee the organisation’s work programme. The secretariat in Monaco includes technical specialists, administrative staff and support personnel.
Much of the organisation’s expertise is supplied by specialists from member states and invited experts from industry, who contribute through numerous committees and working groups. These groups develop and maintain technical standards, produce guidance documents and coordinate international projects.

Hydrographic Capacity and Training

One of the core functions of the organisation is to foster safe navigation by improving global hydrographic capabilities. To achieve this, it develops standards of competence for hydrographic surveyors and nautical cartographers in cooperation with the International Federation of Surveyors and the International Cartographic Association. These standards are used by national hydrographic offices and academic institutions offering hydrography programmes. An advisory board oversees the accreditation of training programmes and ensures their alignment with international requirements.
Capacity-building initiatives support developing states in establishing or enhancing their hydrographic infrastructure. Activities include technical workshops, assessments, resource development and assistance in meeting international charting obligations.

Standardisation of Charts and Surveys

Standardisation has been central to the organisation’s mission since its inception. Regularly updated editions of the Standards of Hydrographic Surveys incorporate advances in technology, ranging from traditional surveying techniques to the integration of electronic navigation systems. The rise of digital navigation in the late twentieth century prompted new requirements for accuracy, data management and interoperability.
The organisation has long worked to standardise the content and format of paper charts. The INT chart system, adopted in the early 1970s, provides a unified chart series that member states must follow when charting the same maritime areas. Publication M-4 established comprehensive specifications for chart symbols, layout and content.
With the development of Electronic Chart Display and Information Systems, the organisation focused on digitisation. It standardised electronic navigational charts—known as ENCs—which are compiled into a global database. Standards governing the transfer, encoding and display of electronic chart data ensure consistency across electronic navigation platforms, contributing significantly to maritime safety.

International and Regional Cooperation

The organisation supports the formation of Regional Hydrographic Commissions. These commissions coordinate surveying and charting activities among neighbouring states and address shared issues such as data sharing, training and regional marine hazards. Fifteen regional commissions, along with a specialised commission for Antarctica, cover most of the world’s maritime regions.
It also works closely with the Intergovernmental Oceanographic Commission, particularly through the General Bathymetric Chart of the Oceans programme, which compiles and distributes global bathymetric data. Cooperation with other international organisations ensures that hydrographic standards align with broader maritime and scientific initiatives.

Technical Achievements and Contributions

The organisation has contributed significantly to the modernisation of marine navigation. Its work includes:

• The creation of international chart specifications and the establishment of the INT chart system.
• The promotion of systematic seabed mapping and ocean observation.
• The standardisation of hydrographic terminology, symbols and maritime measurements.
• The development of geospatial data standards for marine use.
• The enhancement of global maritime safety through rapid dissemination of critical navigational information.

Its publication series includes technical standards, guidelines and reference materials such as the International Hydrographic Review, the Hydrographic Dictionary and the Year Book. These resources are publicly accessible and widely used by hydrographic offices, researchers and maritime professionals.
A key publication is the S-57 Transfer Standard for Digital Hydrographic Data, which defined the encoding system for electronic navigational charts. In 2010 the organisation introduced the S-100 Universal Hydrographic Data Model, an updated standard aligned with the ISO 19100 geographic information series. S-100 supports enhanced marine data products and has been adopted by governmental and private-sector organisations as part of the broader e-navigation initiative endorsed by the International Maritime Organization.
Another publication of interest is S-23, Limits of Oceans and Seas. Its third edition dates to 1953, and although work on a fourth edition began in 1986, publication has been suspended pending resolution of state-level disagreements.