Is there a ferry to Zhuhai from HK Airport please?

Yes, you can take a ferry at Skypier which is inside the airport. When you arrive at the airport, you can follow the signs to find the port. The ferry heading for Zhuhaijiuzhou Port departs at 12:15, 14:15, 17:00 and 20:10 with the duration of 70 minutes. It charges HK$260/adult for an economy class, HK$350 for a first class and HK$385 for a VIP class.