The South Blue is an ocean in the Blue Sea. The South Blue, like its sister seas, comprises almost entirely of ocean, with scattered islands and a border with the Red Line.
The revolver Mr. 5 uses for his Breeze Breath Bomb attack is a new model from the South Blue. The South Blue is also home to an island famous for its martial arts known as Karate Island.
Torino Kingdom: The island where Tony Tony Chopper was sent to by Bartholomew Kuma. The natives are very advanced in terms of technology and medicine despite their primitive looks. Chopper spent 2 years on this island, honing his medical knowledge and skills.
210 years ago before the current time, the ship St. Briss left from the Briss Kingdom carrying a crew towards the Grand Line. The crew reached Skypiea eventually, but something happened once they arrived there and the entire crew was sentenced to Cloud Drifting, likely for major crimes. 208 years later, the St. Briss fell back into the Grand Line before being eaten by a gigantic turtle during an attempt to salvage it. The ship was a wreck, and many would assume a fight had broken out, which may have happened during cloud drifting. Nothing more is known for sure except that the ship was cloud drifting.
During this time period, it was a custom in a certain region of the South Blue for one to coat their teeth with tar in order to preserve them. At least one member of the St. Briss' crew followed this custom, which allowed his teeth to still be firmly attached to his skull even after two centuries.
Portgas D. Rouge, shortly after giving birth to Ace.
24 years ago before the current time, in the island of Baterilla, the Pirate King, Gol D. Roger, was witnessed acting less like a pirate and more like a "father". This led the Marines to start looking for a potential child, by investigating every newborn, every baby going to be born, mothers who were pregnant, and tiny leads from Cipher Pol. Marines scoured Baterilla, looking for any pregnant women, under orders to kill any suspicious ones.
Roger told Monkey D. Garp about his unborn child and trusted the Marine enough as a friend to request the protection of his offspring as he would not be alive anymore by the time his kid arrived. Garp protested, but eventually complied to Roger's request.
Portgas D. Ace's mother, Portgas D. Rouge, was able to avoid the Marines' investigation by keeping the unborn Ace in her womb for a full period of twenty months. The strain caused by her feat led to her death right after giving birth to her child. Gol D. Ace, as his mother named him at birth, ended up being born one year and three months after his father's execution at Loguetown.
