"The rising sea level stuff is not completely correct." -- Wano is a place where the four seas all met at one time, but when the borders were closed, it created a frightening and vicious sea current around the island. In Ancient Times, they called this the "All Blue". The Land of Wa -- The Land of Harmony. Hence why Shokugeki no Sanji was released last week to remind us of all the All Blue. This is my last guess
@Lance_Dragonite , after this Asura, I'm done...wait wrong story.