During the Yongle period of the Ming Dynasty, Zheng He's treasure ship "Cangming" sank in the "Guixu Sea" (a dangerous area with turbulent ocean currents and dense reefs) in the South China Sea due to a severe typhoon. The core treasure is the "Yongle Navigation Secrets" (written on mulberry paper, preserved with special tung oil, and hidden in the secret room of the treasure ship's cargo hold). In addition, there are also manuscripts recording overseas herbal medicine and astronomical observations, which need to be passed through Only by "Three Sea Trials" (breaking ocean currents, finding a lighthouse, and uncovering a secret room) can one reach the location of the sunken ship.
