History of hydronym “Southern Ocean” is long and dramatic. During three and a half centuries outstanding scientists, authoritative scientific congresses, international maritime organizations were either perceive or reject the Southern Ocean as a geographical object. On the basis of the best available synthesis of the works of the last century, the article is traced the struggles and changing views of famous oceanographers, geographers, polar explorers and hydrographs about the problem. The formal boundary of the South Polar Region of the World Ocean on the 60° parallel of south latitude leaves almost entirely outside of the Southern Ocean the Antarctic Circumpolar Current (ACC), which is fundamental feature of the circulation of its waters. Therefore we suggest continuing to define the borders of self-sufficient geographical object the Southern Ocean: on the South by shore line of Antarctic continent, and on the North by the line connecting the southern tip of Africa, Australia, New Zealand and South America. Last line is almost identical with the subtropical convergence.