Copy from http://ivao.hk/pilot/procedures/local-helicopter/
1. Traffic in the Harbour
It was agreed that the high risk area is west of Hung Hom and North Point below 1000 ft. due to helicopters using the Wanchai Helipad, Shun Tak and the Peninsula Rooftop. Pilots are to be advised to keep to the following discipline over the Harbour.
• Fixed wing aircraft to maintain 1500 ft. westbound and 1000 ft. eastbound.
• Helicopters to maintain at or above 1000 ft. when transiting.
2. Pilots are also reminded that it is good practice to report “Green Island” and “Cheung Chau” due to heavy traffic at these two points. (At one time, there was a standing NOTAM making this mandatory. The NOTAM is no longer in force. However, it is still good practice to continue reporting at these two points.)