Before the Treaties of Nanking, Peking and Tientsin reshaped the region between 1842 and 1860, sea traffic around Hong Kong was modest. Those treaties forced the Qing government to open more trading ports, and European merchant vessels began threading through unfamiliar waters in far greater numbers. Waglan Island sat directly on the natural approach from the open South China Sea, making it the obvious sentinel. The lighthouse's layout was designed by David Marr Henderson, Engineer in Chief of the Chinese Maritime Customs, and the original station included living quarters, a freshwater collection tank, and a derrick for hoisting people and supplies onto the island's steep flanks — because without that derrick, there was no other way ashore. The station was managed from Shanghai, and its first keepers were German, a reflection of the international character of the Customs service in those years.

The working team at any given time consisted of one principal keeper, two assistant keepers, five attendants responsible for grass cutting and cleaning, and a cook. Their rotation was demanding: one month on the island, then one week's leave. That schedule placed men in real isolation on a speck of land surrounded by open water, with no ferry stop, no neighbours, and fog signals loud enough to be heard five miles away. Those signals evolved over time. Three 18-pounder cannons were installed in the early British period for fog warnings and defence. By 1923 the cannons were replaced by a twin-type Diaphone — a diesel-powered device producing a two-tone blast, an upper note followed by a longer, lower rumble. In the 1930s two Chinese keepers rose to second-class rank: Wong Kai Chung, arriving in 1930, and Leung Chiu Tung in 1933, both transferred after apprenticeships at Gap Rock Lighthouse. Their promotions represented a shift in how the colonial lighthouse service was staffed.

On 13 December 1941, at 10:30 in the morning, the keeper and his staff were evacuated and taken by boat to Aberdeen. Before they left, the Royal Navy destroyed the original lens, the lamp assembly, and the communication equipment — denial of assets to the approaching Japanese forces. The lighthouse itself was extensively damaged in the months that followed, caught between Japanese occupation and Allied aerial bombardment. When the war ended in 1945, a temporary light was installed to restore some navigational function immediately. The full reckoning came in January 1946, when the Hong Kong Civil Affairs Committee approved HK$2,050,000 for reconstruction and modernisation. Damaged air-raid shelter tunnels were back-filled. The lighthouse was rebuilt to resume its permanent role. What had been destroyed was painstakingly replaced.

In 2000, the Waglan Island Lighthouse was designated a declared monument of Hong Kong — one of five surviving pre-war lighthouses in the territory still standing. The recognition acknowledged more than architectural heritage. Waglan also serves as one of Hong Kong Observatory's key weather stations, recording sea-level meteorological data that feeds into typhoon tracking and marine forecasts. The island's position at the territory's southeastern edge makes it a first point of contact for weather systems moving in from the South China Sea. The lighthouse that merchants once needed to find the harbour mouth now also helps the city understand what the sky is about to do. Two functions, one rock, one hundred and thirty years of unbroken service.

Waglan Island sits at approximately 22.18°N, 114.30°E, about 12 nautical miles southeast of Hong Kong International Airport (VHHH). From a light aircraft at 2,000 feet, it appears as an isolated wedge of rock distinct from the larger Po Toi Islands to its northwest. The lighthouse tower is the island's most visible feature, white against the darker vegetation when the sky cooperates. The waters around it are active shipping lanes — bulk carriers and container vessels tracking inbound to Kwai Chung terminals frequently pass within a few miles. Approaching from the southeast, Waglan provides a clean VFR waypoint before the controlled airspace of Hong Kong's busy terminal area begins to compress routing options.