The Abyss of the South China Sea: The Secret Logbook of Zheng He's Treasure Ship

During Zheng He's seventh voyage to the Western Ocean in the Yongle era of the Ming dynasty, the treasure ship Cangming sank in a violent typhoon in the Guixu waters of the South China Sea, a perilous region said to be rife with chaotic currents and hidden reefs. Its chief treasure was the Yongle Secret Navigation Log, written on mulberry paper and preserved with special tung oil, hidden in a secret compartment in the ship's hold. There were also handwritten manuscripts recording foreign medicinal herbs and astronomical observations. The wreck can only be reached by completing the Three Seas Trials: breaking through the currents, finding the lighthouse, and opening the secret chamber.