Most countries recognize five oceans: the Atlantic, Pacific, Indian, Arctic and Southern, or Antarctic Oceans. Of these, the Atlantic, Pacific, Arctic and Southern are all at least partially located in the Western Hemisphere.
While the Atlantic is almost completely contained within the Western Hemisphere, a small piece of it along the western coast of Africa lies to the east of the meridian at 0 degrees longitude. The Pacific is divided into roughly equal eastern and western halves by the meridian at 180 degrees longitude. The Arctic and Southern Oceans are situated around the north and south poles, respectively, and so are equally a part of both Western and Eastern Hemispheres. Only the Indian Ocean lies entirely in the Eastern Hemisphere.