Global Issues & ODA

The International Hydrographic Organization (IHO) is a competent international organization of a technical nature, referred to in the United Nations Convention on the Law of the Sea, aimed at establishing and harmonizing international standards including for hydrographic products, promoting capacity building of national hydrographic services, and improving the availability and quality of hydrographic data and other related information. The vision of the IHO is to be the authoritative worldwide hydrographic body which actively engages all coastal and interested States to advance maritime safety and efficiency and which supports the protection and sustainable use of the marine environment.

The International Hydrographic Bureau was established in 1921, and International Hydrographic Organization (IHO) was established in 1970, under the Convention on the International Hydrographic Organisation, adopted in 1967. In 2016, the Protocol of Amendments to the Convention on the International Hydrographic Organization entered into force. The IHO has 104 Member States /Area at the moment. Its headquarters are located in Monaco.

Currently, Dr. Mathias Jonas (Germany) serves as Secretary-General. Rear Admiral Luigi Sinapi (Italy) was elected as the next Secretary-General at the IHO Assembly in April 2026, and is scheduled to take office in September 2026.

“Limits of Oceans and Seas (S-23)” is an IHO publication designed to serve as guidelines on the limits of oceans and seas for the benefit of national hydrographic offices in compiling nautical charts.

“Limits of Oceans and Seas (S-23)”, from its first edition of 1929 to the latest third edition of 1953, consistently uses Sea of Japan as the sole internationally established name to refer to the sea area concerned.

Since the 1990s, the Republic of Korea (ROK) has argued that the name Sea of Japan should either be changed to "East Sea," or that both names be used together on governmental and commercial maps and maps for use by international organizations. In 1997, the ROK started making such a claim also at the IHO.

(3) Recent Trend and S-130

The 2nd session of the IHO Assembly in 2020 decided that S-23 is kept publicly available as part of the existing IHO publications, and approved the development of a dataset named “Polygonal demarcations of global sea areas (S-130)”, with the aim of digitizing ocean boundaries and managing them with numerical identifiers. The S-130 dataset was approved at the 4th session of the IHO Assembly in 2026.

Despite ROK’s claim regarding the name “Sea of Japan,” the sole designation of “Sea of Japan” in “Limits of Oceans and Seas (S-23)” has not been changed; furthermore, at the 2nd IHO General Assembly in 2020, it was decided that “Limits of Oceans and Seas (S-23)” would continue to be an IHO publication available to the public. Going forward, Japan will continue to assert its position on the name “Sea of Japan” at every opportunity, based on its fundamental stance that “Sea of Japan” is the sole name established internationally and historically, and that there is neither a need nor a ground for any change to the sole designation of “Sea of Japan”.