Episode 727
Luffy’s Ultimate Test! The Battle for the Future of the Sea
Japanese: ルフィの究極の試練!海の未来をかけた戦い
Rufi no Kyūkyoku no Shiren! Umi no Mirai o Kaketa Tatakai
After leaving the ghost ship, the Straw Hats encounter a floating island held aloft by mysterious forces. The island is inhabited by a civilization that has developed advanced technology. However, the island’s rulers are oppressive and use their technology to keep the inhabitants in fear. The crew must decide whether to intervene and free the islanders.