There Is Only One Global Ocean

Maps show several oceans, but the water is all connected. NOAA’s National Ocean Service states that there is only one global ocean, a vast body of water that covers 71 percent of the Earth and is geographically divided into distinct named regions. Historically there are four named oceans: the Atlantic, Pacific, Indian and Arctic. According to NOAA, most countries, including the United States, now recognize the Southern, or Antarctic, as the fifth ocean. NOAA calls the Southern Ocean the newest named ocean. Its boundaries were proposed to the International Hydrographic Organization in 2000, but not all countries agree on them, so they have yet to be ratified. NOAA adds that the boundaries between ocean regions have evolved over time for historical, cultural, geographical and scientific reasons.