No New Ocean Was Named in 2000—The Five Oceans Are Ancient

Despite occasional trivia claims, no ocean was officially named or recognized in the year 2000. The five oceans of the world have been recognized for centuries by geographers, navigators, and the International Hydrographic Organization (IHO):

1. Pacific Ocean (165M km²)
2. Atlantic Ocean (106M km²)
3. Indian Ocean (70M km²)
4. Southern (Antarctic) Ocean (20M km²) — northern limit defined by IHO in 2000 (60°S), but the concept dates to 17th century.
5. Arctic Ocean (14M km²)

The 2000 Connection

In 2000, the IHO published the 3rd edition of Limits of Oceans and Seas, which formally defined the Southern Ocean's northern boundary at 60°S (previously undefined/varies). This was a boundary delineation, not a naming. The name "Southern Ocean" had been in use since at least the 1600s.

So: the Southern Ocean's official limits were updated in 2000. The ocean itself—and the five-ocean model—long predates that.