Hello, can I just take train from nanjing to guangzhou? then I take ship from guangzhou to hainan?

Go to Nanjing South Railway Station, where there are two high speed trains to Guangzhou. It takes 7-8h. The cost is CNY610-630 for a second class seat and CNY910-940 for a first class seat.

Regular ships to Haikou have been out of service now. As I know, only Coconut Princess Cruise is arranged. I heard it leaves every Tues. Thur. and Sat. from Nansha Shazaidao Dock. The fare will range from the cabin classes. The cruise will go to Haikou Xiuying Dock by the way.

High speed train is the best way to travel between Haikou and Sanya. Go to Haikou Railway Station or the East Railway Station to take one to get within 2-2.5h. The ticket fare will range from CNY90 to CNY215.

Have a good time!