The former Warlord Gecko Moria and his crew previously resided in the Florian Triangle on their ship, Thriller Bark. Because of this, the Florian Triangle serves as the overarching setting of the Thriller Bark Saga.
The Florian Triangle is masked in incredibly thick fog that covers the entire sea. The fog is dense enough to completely block out sunlight and make it impossible to tell whether it is night or day. However, it is not a permanent fixture of the sea. At the end of the Thriller Bark Arc, the sky cleared and revealed the sun during the daytime for multiple days before the fog returned.
Many people travel through the Florian Triangle, as it is necessary to do so to follow the sea route from Water 7 to Fish-Man Island. Gecko Moria set up Thriller Bark inside of the Florian Triangle to take advantage of its heavy traffic. He was able to capture people traveling through the sea and steal their shadows to build his zombie army.
Over 100 ships disappear every year in the Florian Triangle and are often found later without their crews. While some of these disappearances are due to Moria's scheme, ships in the area vanished long before the arrival of Thriller Bark. The cause of this appears to be unidentified entities that dwell within the Florian Triangle. Nothing is known about these entities, except that they are massive and appear to have red eyes. They are large enough to completely dwarf Thriller Bark, an island-sized pirate ship. Despite their size, they are able to conceal themselves within the fog and remain undiscovered. Charlotte Lola was barely able to notice them through the fog.
Ships began disappearing in the Florian Triangle a long time ago, very long before Moria and Thriller Bark arrived 12 years ago.
52 years ago, the Rumbar Pirates sailed into the Florian Triangle and were attacked by another pirate crew. Everyone on their ship died except for Brook, whose soul returned to his body after being lost in the fog for a year. Because the ship's rudder was broken, Brook drifted aimlessly in the Florian Triangle for the next 44 years, inspiring rumors of a ghost ship manned by a dead crew due to his skeletal appearance.
12 years ago, Gecko Moria and his crew anchored Thriller Bark in the Florian Triangle. They captured any ships that sailed into the sea using barrels with signal flares to mark them. Moria used his Devil Fruit ability to steal the shadows of his victims before sending them back out to sea.
7 years ago, Brook came across Thriller Bark and searched the island, hoping for a way to fix his ship's rudder. However, his shadow was stolen by Moria and, after returning to the island a second time, he was ultimately forced back out to sea where he drifted for another 5 years.
Thriller Bark Saga
While traveling to Fish-Man Island, the Straw Hat Pirates came across and accidentally set off one of Moria's signal flare barrels, making themselves targets of the Thriller Bark Pirates. Soon after, a storm forced the crew into the Florian Triangle, where they met Brook. The Straw Hats and Brook were then taken in by Thriller Bark, and Luffy, having befriended Brook, decided to fight Moria in order to recover Brook's shadow.
After Moria was defeated, he abandoned the island and fled the Florian Triangle with what remained of his crew. With their shadows returned, Brook and Moria's other victims who were stuck on Thriller Bark were finally able to leave the Florian Triangle.
After the Timeskip
At some point after the timeskip, Perona returned to the Florian Triangle to find Kumashi's corpse on Thriller Bark. Moria later returned to reclaim the ship and removed it from the foggy stretch of sea.
- The Florian Triangle is based on the Bermuda Triangle. This real-world region of the ocean is the subject of urban legends, which claim that many ships and aircrafts have mysteriously disappeared while traveling through.
- The kanji that make up the Florian Triangle's name are identical to the kanji used in the "Devil's Triangle" (魔の三角地帯 Ma no Sankaku Chitai?), the other common name of the Bermuda Triangle.
- The name "Florian" is likely derived from the name of the American state of Florida, which is one of the three locations that make up the points of the Bermuda Triangle. The first three characters in the Japanese spellings of "Florian" (フロリアン Furorian?) and "Florida" (フロリダ Furorida?) are the same.
- The mysterious entities living in the Florian Triangle greatly resemble traditional depictions of umibōzu, enormous sea monsters said to drown sailors.
- Coincidentally, when the Straw Hat Pirates first learned about the Florian Triangle from Kokoro, some of them made casual comments about what they thought they might encounter there, all of which came true in some form:
- Chopper feared that they might encounter ghosts, which they did, in the form of Perona and her ability.
- Luffy hoped that they might meet a living skeleton, which they did, in the form of Brook.
- Nami feared that they might run into ghost ships, and they technically encountered two: the Rumbar Pirates' old ship and the other Thriller Bark.
- Robin mentioned rumors of ghost ships containing treasure, and Thriller Bark held a vast horde of it.
- Zoro hoped that he could find a sword among the treasure, and his hope was answered when he acquired Shusui after defeating Ryuma.