Need to visit a Cruise at Chinese Port

Hi Sir,
I work for a ISP and one of our Cruise customer will be enchoring at chinese Sea Port where I need to visit them for training the crew on board, so which type of VISA should I apply, I will go by air to China than from their will board on that Cruise while it will be in China Sea Port stay their for 3 or 4 days and than will return back from Airport.

Regards
Ali Iqbal