C422 The Purpose of Zheng He's Going to Sea

At the other end of the deep pool below the waterfall, there was a sailboat docked at the shore. The sailboat was very large, but it was extremely old.

Chinese characters, Chinese sailboat. Why would there be a sailing ship on this island?

Could it be that this was driven by the Immortal Island pursuers when Emperor Han Wu was still the emperor? But that's impossible