Since 40 AG, the Fire Nation Navy conducted the Southern Water Tribe raids from the South Sea. Over time, the Fire Nation military activity in the area decreased. By the latter stages of the Hundred Year War, only the Southern Raiders were still active in larger numbers in the South Sea. They consistently raided the coastal settlements of the southern Earth Kingdom and the Southern Water Tribe.
After the end of the Hundred Year War, the South Sea became a place of great commercial activity with many transport ships, such as large steamships, passing through it. However, several ships in the Southern Water Tribe's waters were attacked by dark spirits in 171 AG.
Northern Water Tribe battleships formed a blockade around the South Pole during the Water Tribe Civil War. While passing through the South Sea, one Northern battleship that transported prisoners of war was attacked by Team Avatar.
The South Sea extends from the southern coast of the continental Earth Kingdom to the islands that form the nation's southernmost territories. It also spans from Whaletail Island and the former Air Nomad territories to the west to the narrow strait between the Earth Kingdom and the central of three large islands in the east. Activity in the South Sea is infrequent: while Kyoshi Island is a somewhat popular destination among traders and travelers, there is minimal military traffic, as the bordering areas have little strategic importance.
The Earth Kingdom coastline bordering the sea is fairly uneven, with a large inlet at the mouth of the Nan Shan River. The only coastal city of note is Chin Village. Though the sea is bordered by several large islands, including Whaletail Island, the only island of note in the area is Kyoshi Island.
The South Sea is rich in marine life, including many species of fish, like the elephant koi, and sea serpents, like the unagi. As such, fishing is a major industry in surrounding regions. However, the waters of the South Sea's sections close to the South Pole are cold enough to kill humans in minutes and populated by vast icebergs.