Hydrographic Data Codes

IHO 23-4th: Limits of Oceans and Seas, Special Publication 23, Draft 4th Edition 1986, published by the International Hydrographic Bureau of the International Hydrographic Organization.

IHO 23-3rd: Limits of Oceans and Seas, Special Publication 23, 3rd Edition 1953, published by the International Hydrographic Organization.

ACIC M 49-1: Chart of Limits of Seas and Oceans, revised January 1958, published by the Aeronautical Chart and Information Center (ACIC), United States Air Force.

DIAM 65-18: Geopolitical Data Elements and Related Features, Data Standard No. 4, Defense Intelligence Agency Manual 65-18, December 1994, published by the Defense Intelligence Agency.

The US Government has not yet adopted a standard for hydrographic codes similar to the Federal Information Processing Standards (FIPS) 10-4 country codes. The names and limits of the following oceans and seas are not always directly comparable because of differences in the customers, needs, and requirements of the individual organizations. Even the number of principal water bodies varies from organization to organization.  Factbook users, for example, find the Atlantic Ocean and Pacific Ocean entries useful, but none of the following standards include those oceans in their entirety. Nor is there any provision for combining codes or overcodes to aggregate water bodies. The recently delimited Southern Ocean is not included.

Body of WaterIHO 23-4thISO 23-3rd*Acic M 49-1DIAM 65-18
Arctic Ocean917A5A
Atlantic Ocean----
Baltic Sea21B267B
Eastern Mediterranean3.1.228 B-8E
Indian Ocean545F6A
Mediterranean Sea3.128B11-
North Atlantic Ocean123B1A
North Pacific Ocean757D3A
Pacific Ocean----
South Atlantic Ocean432C2A
South China and Eastern Archipelagic Seas649, 48D18 plus others3U plus others
South Pacific Ocean861E4A
Western Mediterranean3.1.128 A-8W