Guangdong

Guangdong's South China Sea coast runs from the Pearl River Delta in the centre to the Leizhou Peninsula in the southwest — a 1,500 km coastline where the tidal character shifts with latitude and coastal geometry. The dominant regime is mixed semidiurnal: two unequal high waters and two unequal low waters per day, with the inequality between them large enough that one high is often significantly taller than the other. Mean ranges are modest by global standards — 1.0 to 1.5 m through most of the Pearl River Delta, rising to approximately 2.0 m at Zhanjiang where the South China Sea exposure is greatest. The Pearl River Delta is the most complex tidal geography in the province. The Pearl River distributes its flow through eight outlets (the 'Eight Outlets' system), and tidal currents penetrate far inland through the distributary network. Zhuhai on the western estuary bank connects to Macau by a short ferry crossing; the Hong Kong–Zhuhai–Macau Bridge (55 km, opened 2018) crosses the estuary's outer channels and is the longest sea-crossing bridge in the world. Tidal currents through the bridge's channels are a significant factor in its marine engineering. The Dapeng Peninsula, projecting southeast from Shenzhen into Daya Bay, is the only stretch of undeveloped coast remaining near China's third-largest city. Dongchong and Xichong beaches at the peninsula's southern tip are accessible only by boat or by a 5 to 8 km hiking trail; the absence of roads has preserved them. Low water exposes tidal reef platforms for walking — a rare coastal experience within an hour of a megacity. Zhanjiang, at the base of the Leizhou Peninsula in southern Guangdong, sees the largest tidal range in the province (approximately 2.0 m mean) due to its open South China Sea exposure. Donghai Island, connected to the mainland by causeway, has a notable 30 km beach on its eastern side. Authoritative tide data for all Guangdong locations is published by the State Oceanic Administration / National Hydrographic Centre (SOA/NHC).