The Calm Belts are very effective barriers for those trying to enter and exit the Grand Line; these areas are always completely calm, never having any ocean currents or winds blowing, making it impossible for non-self propelled ships to travel through. They also happen to be the nesting grounds for the world's largest Sea Kings, which attack any ship attempting to cross over. For this reason, the safest method for any ship from the East, North, West or South Blue to enter the Grand Line, and vice-versa, is by traveling over Reverse Mountain, which is also risky in its own right.
It was then revealed that the Marines are able to safely cross the Calm Belts by using Seastone lining at the bottom of their ships. This usually prevents the Sea Kings from noticing ship above them, but not always.[1]
Locations[]
There are several islands that are scattered across the Calm Belt, though these islands are also considered highly dangerous.
Amazon Lily, home of the Kuja tribe, is one of the few inhabited locations within one of the Calm Belts. Its location within a Calm Belt has historically guarded the island from intruders. However, this protection has degraded somewhat due to the Marines' newly invented technique of shielding their boats from Sea Kings with Seastone.[2]Silvers Rayleigh is the only known person so far to have reached Amazon Lily by swimming and without much hindrance by the Sea Kings.[3]
Another natural island in the Calm Belt is the island of Rusukaina, which is located northwest of Amazon Lily.[4]
The Great Prison, Impel Down, is built in the middle of the Calm Belt,[5] upon the seafloor. Because of the heavy security and Sea Kings, it is almost impossible to break in or out of it.[6] However, 22 years ago, Shiki the Golden Lion managed to escape by cutting off his shackled legs.[7] Then, two years ago, Monkey D. Luffy managed to slip into the prison and break out with 241 prisoners, including Buggy, Jinbe, Emporio Ivankov, Crocodile and several others. Blackbeard also broke in and recruited some of the most heinous criminals in history into his crew, as well as the disgraced jailer, Shiryu.
History[]
52 years ago, Captain "Calico" Yorki of the Rumbar Pirates is said to have attempted to flee the Grand Line via one of the Calm Belts after he and several other crewmates contracted a deadly disease.[8] Their fate is unknown but it is said that they perished before escaping that Calm Belt.
2 years ago, the Straw Hat Pirates inadvertently entered one of the Calm Belts and encountered the Sea Kings living in it, but then luckily managed to escape when their ship was sneezed away by a larger Sea King whose head they were sitting on.[9]
Trivia[]
The Calm Belts may be based on the real life horse latitudes (also known as doldrums), which are the 30° latitudes surrounding the equator where weak winds historically led to ships becoming stranded.