If the owner's seal and epitaph are excavated in a tomb, it can be determined that the tomb is the real Tomb of the owner. In the Xigaoxue tomb, the seal and epitaph of Cao Cao are not excavated. 
the Xigaoxue tomb is not the real Tomb of Cao Cao.
Only with a deep-water certificate can he enter the deep pool. He can't enter the deep pool because he doesn't have a deep-water certificate