how can I take a boat from haikou to guiyang and how does it cost?

There is no boat between the two places, but you can try the long-distance bus or trains to Guiyang.
There is only one train between and it is K486/K487. The hard sleeper costs around 354.5 to 381.5RMB per person based on different layers.
From HK West Bus Station, there is direct bus to Guiyang, but i am sorry that I am not very clear about the timetable and the exact price.