International Hydrographic Organization

The International Hydrographic Organization (IHO), known in French as the Organisation Hydrographique Internationale, stands as a beacon of intergovernmental cooperation, representing the specialized field of hydrography . Established on 21 June 1921, this organization has spent over a century ensuring the world’s maritime environments are meticulously mapped and understood. As of August 2025, the IHO boasts a membership of 103 states, though a couple are currently in a suspended status, a detail one can explore further in the List of Members of the International Hydrographic Organization . Its official languages are English and French , a testament to its global reach and historical roots. The current Secretary-General is Mathias Jonas, and its operational hub is situated in Monaco .

Core Mission and Objectives

At its heart, the IHO’s primary objective is to guarantee that the world’s seas, oceans, and all navigable waters are comprehensively surveyed and accurately charted. This monumental task is achieved through the establishment and enforcement of international standards for hydrographic practices and through the deployment of capacity-building programs and regional offices. The organization’s influence extends to the global stage; it holds observer status at the United Nations , where it is recognized as the definitive authority on hydrographic surveying and nautical charting . Consequently, when international conventions and legal instruments refer to hydrography and nautical charting, it is invariably the standards and specifications laid out by the IHO that are invoked.

A Glimpse into History

The seeds of the IHO were sown in the 19th century, a period marked by the burgeoning efforts of numerous maritime nations to establish dedicated hydrographic offices. These offices were crucial for enhancing the safety and efficiency of naval and merchant vessels by providing essential navigational aids like nautical publications and charts. However, a significant challenge emerged: the considerable discrepancies in hydrographic procedures, chart formats, and publication styles across different nations. This fragmentation prompted calls for greater standardization.

The first significant international dialogue occurred in 1889 at the International Maritime Conference held in Washington, D.C. . Here, the concept of establishing a “permanent international commission” was first put forth. Similar proposals surfaced at subsequent international gatherings, including the International Congress of Navigation sessions in Saint Petersburg in 1908 and another International Maritime Conference, also in Saint Petersburg , in 1912. These discussions highlighted the growing need for a unified approach to hydrographic matters.

The pivotal moment arrived in 1919 when the national Hydrographers of Great Britain and France collaborated to organize an international conference specifically for hydrographic experts. London was chosen as the venue, and on 24 July 1919, the First International Conference commenced, drawing participation from the Hydrographers of 24 nations. The conference’s agenda was ambitious, aiming to “consider the advisability of all maritime nations adopting similar methods in preparation, construction, and production of their charts and all hydrographic publications; of rendering the results in the most convenient form to enable them to be readily used; of instituting a prompt system of mutual exchange of hydrographic information between all countries; and of providing an opportunity to consultations and discussions to be carried out on hydrographic subjects generally by the hydrographic experts of the world.” Remarkably, these objectives remain the central purpose of the IHO to this day.

Following the 1919 Conference, a permanent organization was formally established, and statutes governing its operations were meticulously drafted. The International Hydrographic Bureau (IHB), the precursor to the IHO, officially began its work in 1921 with 18 founding member nations. The Principality of Monaco was selected as the headquarters, a decision facilitated by the generous offer of Albert I of Monaco to provide suitable accommodation for the Bureau within his principality.

The organization was formally constituted as the International Hydrographic Organization in June 1921, initially operating as the International Hydrographic Bureau (IHB). Vice Admiral Sir John Parry, KCB of the United Kingdom, had the distinction of serving as its first President. The significant transformation into the International Hydrographic Organization, under its current name, occurred in 1970. This rebranding was part of a new International Convention on the IHO, agreed upon by its member nations, with Guy Chatel of France playing a key role in its leadership during that era. The designation “International Hydrographic Bureau” continued to refer to the IHO’s secretariat until 8 November 2016. On this date, a substantial revision to the Convention took effect, leading to the renaming of the secretariat to the “IHO Secretariat.” This secretariat is now headed by an elected Secretary-General, assisted by two Directors and a small permanent staff, numbering 18 in 2020, all based at the organization’s headquarters in Monaco.

Organizational Structure

Prior to the 2016 revisions, the IHO was managed by a secretariat overseen by a Directing Committee, which consisted of a President and two Directors. Since 8 November 2016, following the implementation of amendments to the Convention on the IHO, the secretariat has been led by a Secretary-General. This role is supported by two Directors, and the first individual to hold this position under the revised structure was Robert Ward from Australia. All three senior positions within the secretariat are filled through elections by the Member States during the regular Assembly of the IHO (previously known as IHO Conferences).

The secretariat’s staff comprises a team of technical specialists, administrators, and support personnel. However, the bulk of the IHO’s technical acumen and specialized knowledge is drawn from the personnel of its Member States. These individuals, often augmented by invited experts from industry, contribute their technical expertise through active participation in various IHO committees and working groups.

Overseeing the IHO’s work is a Council, composed of a selected subset of all IHO Member States. This Council convenes annually to review and guide the organization’s ongoing activities. A comprehensive overview of the IHO’s structure, including detailed information on the functioning of all its various bodies, is readily available on the IHO’s official website.

Key Functions and Responsibilities

The IHO plays a critical role in ensuring maritime safety by developing hydrographic survey capabilities and establishing robust nautical charting standards. To foster and standardize the hydrographic survey skills of its member states, the IHO has collaborated closely with the International Federation of Surveyors (Fédération Internationale des Géomètres) and the International Cartographic Association (ICA). This partnership led to the creation of the IHO’s Standards of Competence, which serve as the benchmark for educating and training hydrographic offices and nautical chart producers within member nations. Furthermore, the IHO develops comprehensive syllabi for higher education institutions offering courses in hydrography and nautical navigation. An advisory board is also in place, tasked with the crucial responsibility of supervising and approving the educational and training programs put forth by member states.

Standardization Efforts

Since 1968, the IHO has consistently published updated editions of its Standards of Hydrographic Surveys, with the most recent iteration dating back to 2008. Each revision has been meticulously designed to integrate technological advancements and address the evolving demands of international shipping. This commitment to adaptation is particularly evident in response to the significant rise of electronic navigation equipment, which gained prominence throughout the 1980s.

Beyond survey standards, the IHO dedicates substantial effort to standardizing the specifications, visual style, and symbols employed in the production of nautical charts. A notable achievement in this regard was the member states’ agreement in 1971 to adopt a single, unified chart series, commonly referred to as INT charts. This agreement stipulated that if a member state intended to publish a chart for an area already covered by an existing chart from another member, the duplicate chart must meticulously adhere to the data specifications of the original. Further solidifying these standards, the IHO Publication M-4, first published in 1984, laid down specific international guidelines for the production of nautical charts.

The advent of the Electronic Chart Display and Information System (ECDIS) presented a new imperative for the IHO: to standardize the transfer and display of electronic navigational data aboard ships. This led to the standardization and categorization of electronic chart data into an international database known as Electronic Navigational Charts (ENCs). The processes for transferring this data from producers to end-users were also standardized, as were the display capabilities of ECDIS itself.

Promoting International Cooperation

The IHO actively encourages the formation of Regional Hydrographic Commissions (RHCs). These commissions serve as vital platforms for coordinating the national surveying and charting activities of countries within specific geographical regions. They also function as forums for addressing other hydrographic matters of mutual interest. Currently, there are 15 RHCs, complemented by the IHO Hydrographic Commission on Antarctica, collectively covering the entire globe. In a significant collaborative effort, the IHO, in partnership with the Intergovernmental Oceanographic Commission, directs the General Bathymetric Chart of the Oceans program.

Notable Achievements

The IHO’s contributions to global maritime safety and efficiency are manifold. Key achievements include:

• The establishment of the Chart Specifications Committee, which has been instrumental in developing and refining the standards for nautical charts.
• The creation and promotion of International Charts (INT charts), fostering a unified approach to charting across member nations.
• Facilitating the exploration of the seabed and the understanding of marine environments.
• The Standardization of crucial maritime measurements, hydrographic terminology, marine cartographic products, and the implementation of geographical information systems specifically for navigation.
• Ensuring the high efficiency of the rapid dissemination of vital safety information at sea.
• Providing essential training and professional development for hydrographers and nautical cartographers worldwide.

Publications and Standards

A significant portion of the IHO’s publications, including its comprehensive standards, practical guidelines, and related documents such as the International Hydrographic Review, International Hydrographic Bulletin, the Hydrographic Dictionary, and the Year Book, are made freely available to the public via the IHO website. These resources are invaluable for anyone involved in hydrography and maritime navigation.

Among its most critical publications are the international standards related to charting and hydrography. S-57, the IHO Transfer Standard for Digital Hydrographic Data , is a prime example, serving as the encoding standard primarily used for electronic navigational charts .

In 2010, the IHO introduced S-100, a novel and contemporary hydrographic geospatial standard designed for modeling marine data and information. S-100 and its associated product specifications are supported by an online registry accessible through the IHO website. Crucially, S-100 is aligned with the ISO 19100 series of geographic standards, ensuring its seamless compatibility with modern geospatial data standards.

Because S-100 is built upon the ISO 19100 framework, it can be utilized by a wide range of data providers for their maritime-related data and information, extending beyond purely hydrographic applications. Various governmental and private sector entities are now adopting S-100 as a foundational element in the implementation of the e-Navigation concept, which has received endorsement from the UN International Maritime Organization (IMO).

Another significant publication in the IHO’s repertoire is S-23, titled Limits of Oceans and Seas . The third edition of this work dates back to 1953, while a proposed fourth edition, initiated in 1986, has remained in draft form since 2002. This draft has been circulated among IHO members, but its official publication has been deferred pending an agreement between South Korea and Japan concerning the internationally recognized standard name for the body of water known as the “Japan Sea ” in the 1953 edition. This dispute highlights the complex geopolitical considerations that can arise even in the seemingly technical realm of geographical nomenclature.