International Hydrographic Organization

Lore & Background

The IHO sets standards for hydrographic surveys (updated since 1968) and nautical chart specifications, including the INT chart series (1971) and Publication M-4 (1984). It also standardized electronic navigational data through Electronic Navigational Charts (ENCs) and the Electronic Chart Display and Information System (ECDIS). The organization encourages Regional Hydrographic Commissions and, with the Intergovernmental Oceanographic Commission, directs the General Bathymetric Chart of the Oceans program.

Reader's Guide

The IHO's significance lies in its role as the global authority for hydrographic standardization, ensuring safety of navigation through uniform charts, surveys, and data exchange. Its standards, such as S-57 and S-100, are used in international conventions and by maritime nations. By coordinating regional commissions and training programs with the International Federation of Surveyors and the International Cartographic Association, the IHO has increased mapping of unsurveyed ocean areas and improved dissemination of safety information. Its observer status at the United Nations reinforces its influence on maritime policy. The organization's legacy includes near-global adoption of hydrographic terminology, marine cartographic products, and geographic information systems for navigation, as well as accreditation standards for hydrographers and cartographers.

Did You Know?

• The IHO was originally established in June 1921 as the International Hydrographic Bureau.
• Its headquarters in Monaco were provided by Prince Albert I of Monaco.
• The IHO adopted its current name in 1970 under a new International Convention.
• As of early 2025, the IHO comprised 100 member states.