The Aids to Navigation and Mooring Unit (ANMU) of the Marine Department is responsible for providing and maintaining Aids to Navigation (AtoN) in Hong Kong waters according to the guidelines of the International Association of Marine Aids to Navigation and Lighthouse Authorities (IALA) to ensure the safe and smooth movement of vessels to and from our port.

ANMU maintains over 600 aids, of which about 160 are lighted buoys, 320 are beacons, and 120 are pier lights. There are two vessels and one light good vehicle in the unit for maintenance teams to use. In addition, Government Flying Services would provide helicopter service for conveying the maintenance teams to remote sites to maintain the AtoN, such as Waglan Island, Black Point and Ping Chau.

In the past, acetylene was adopted as fuel for the gas-operated lantern which was ignited by a pilot flame. Then electric-operated lantern was applied with batteries and lamp bulbs. With the automation of the Lighthouses, there is no need for personnel to be stationed and on watch at the Lighthouses. Nowadays, over 90% of lanterns are operated with renewable energy "solar energy". The existing lanterns with batteries and lamps are being replaced by more energy-saving LED lanterns.