e 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.

Principal Oceans and Seas of the World With Hydrographic Codes by
Institution IHO
23-4th IHO
23-3rd* ACIC
M 49-1 DIAM
65-18
Arctic Ocean 9 17 A 5A
Atlantic Ocean - - - -
North Atlantic Ocean 1 23 B 1A
South Atlantic Ocean 4 32 C 2A
Baltic Sea 2 1 B26 7B
Indian Ocean 5 45 F 6A
Mediterranean Sea 3.1 28 B11 -
Eastern Mediterranean 3.1.2 28 B - 8E
Western Mediterranean 3.1.1 28 A - 8W
Pacific Ocean - - - -
North Pacific Ocean 7 57 D 3A
South Pacific Ocean 8 61 E 4A
South China and Eastern Archipelagic Seas 6 49, 48 D18 plus others 3U
plus others

Oceans and Seas of the World With Hydrographic Codes by Institution
IHO
23-4th IHO
23-3rd* ACIC
M 49-1 DIAM
65-18
ARCTIC OCEAN 9 17 A 5A
East Siberian Sea 9.1 11 A6 5S
Laptev Sea 9.2 10 A5 5P
Kara Sea 9.3 9 A4 5K
Barents Sea 9.4 7 A2 5B
White Sea 9.5 8 A3 5W
North Greenland Sea 9.6 - - -
Norwegian Sea 9.7 6 B30 5N
Iceland Sea 9.8 - - -
Davis Strait 9.9 15 B2 1V
Hudson Strait 9.10 16 A A15 1U
Hudson Bay 9.11 16 A10 1H
Baffin Bay 9.12 14 A A12 1P
Lincoln Sea 9.13 17 A A13 5L
Northwest Passages
(Northwest Passage, Northwestern Passages)