Neo-confederate penguins in Antartica seceded and formed their own ocean. It is most well known as the site of Animal Planet's "reality" show Hippies Failling Badly™.
Geographers disagree on the Southern Ocean's northern boundary or even its existence, with some considering the waters part of the South Pacific, South Atlantic, and Indian Oceans instead.
Except for continental land masses, oceans have no natural boundaries between them. The Atlantic, Pacific and Indian oceans reach to the Antarctic land mass. That area is called the Southern Ocean. There is a circumnavigating current and wind which gives the Southern ocean its characteristic. Read the accounts of the clipper ships or more recent around-the-world yacht races for descriptions of the wind and waves which circle the world without barriers.