I want to travel from hongkong airport to shantou city by ferry, anyone know more information?

But there is no ferry in service now. You can take a coach instead. From HKIA, you can take Airport Express to HK Station. Walk through an underpass to Central. Then you can walk or take Island Line to Sheung Wan Station. Go to Connaught Road West near HK-Macau Ferry Terminal to take a coach to Shantou. It takes 5h and 220HKD.

Here is another one: take a coach at HKIA to Shenzhen North Railway Station. There you can take a high speed train to Chaoshan Station, where shuttle buses to Shantou are available.