From Zhuhai to HKIA, and Travel to Tung Chung Outlets before catching flight

Yes, you can take a ferry at Jiuzhou port to HK China Ferry Terminal. This ferry departs at 08:00, 10:00, 11:45, 14:00, 16:00 and 17:00. The ticket of the general class will cost CNY175/person, while the first class will charge CNY265/person. Besides, the VIP class will cost CNY295/person. Upon arrival, you can walk 650 meters northwards to Keshidian Metro Station and take metro Xitie line to Nanchang Station. Then you may transfer Dongyong line to Dongyong Station, Exit C. When you arrive, you can see it directly.

Hi Frek, thank you for your reply.

Can I also take this route instead: Liuzhou → SkyPier (HKIA), where I leave my luggage at the Airport and go to Tung Chung citygate outlets? Or is that not advisable?

Also, could you advise where Keshidian is in HK? Can't seem to locate it on googlemaps.

Many thanks for your assistance.

As I know, you can’t follow this route. If you take a ferry to Skypier, then you can’t go out of the airport to the city center and you can only wait for your departing flight at the airport.
Keshidian Metro Station is just near the HK China Ferry Terminal. When you get out of the terminal, you can walk northwards to Keshidian Station directly.