Quanzhou tide times

Quanzhou Bay opens onto the Taiwan Strait at the mouth of the Jin River, and the spring tidal range here reaches approximately 5.0 m above MLLW — the largest of the three main Fujian ports covered here. The bay is semidiurnal with marked diurnal inequality, and the wide tidal flat at the head of the bay drains to reveal several square kilometres of working intertidal aquaculture at low water.

Quanzhou's status as China's largest medieval trading port is now recognised by UNESCO. The city's Maritime Silk Road inscription in 2021 encompasses 22 heritage components — not a single monument but a system of docks, warehouses, temples, and city infrastructure that together document the mechanics of long-distance maritime trade in the 10th to 14th centuries. The Luoyang Bridge, completed in 1059, spans a tidal estuary north of the city. It was built using an innovative technique: engineers floated stones on rafts at high tide and positioned them on the submerged bridge piers, then waited for the tide to ebb and lower the stones into place. It is one of the earliest examples of deliberate tidal engineering in Chinese construction.

Chongwu Ancient City sits on a headland 40 km northeast of Quanzhou city, where the Fujian granite coastline meets the sea in a series of rocky coves. The Ming-dynasty city wall runs along the clifftop to within a few metres of the tidal zone. Below it, granite fishing villages have operated on the tidal cycle for centuries — boats launch 2 hours before high water and return 3 hours after, timing dictated by the bar at the harbour entrance. The intertidal zone below the city wall supports oyster and clam culture on hand-worked stakes and nets.

The Mazu Temple at Chongwu is one of many along the Fujian coast dedicated to the sea goddess whose birthplace is traditionally located at Meizhou Island, 80 km to the north. Fishing families throughout the bay make offerings before tides that matter — before a spring tide opening the clamming season, before a vessel's first voyage of the year. The temple calendar follows the lunar tide cycle, with major festivals at the first and fifteenth of the lunar month corresponding roughly to spring tides.

Intertidal oyster and clam harvesting in Quanzhou Bay is conducted primarily by women from the fishing villages. The work is tidal-dependent: the beds are accessible only during the 2–3 hours of low water on each tidal cycle, and the harvesters time their walk out onto the flat to the minute. At low water on a spring tide the flat drops 5 m vertically and several hundred metres horizontally from the seawall. The harvesters work outward on the ebb, collect from the beds, and return before the flood rises past knee height on the flat.

Quan oyster (local Crassostrea species) and littleneck clams (Ruditapes philippinarum) from this bay are sold at the daily market in Chongwu fishing village, where vendors set up on the quayside as the morning boats return. The market operates on tidal time — arrival depends on the day's high water, not the clock.

The fishing fleet in Quanzhou Bay still uses wooden-hulled vessels alongside fibreglass hulls, and the anchoring pattern on the tidal mudflat outside Chongwu harbour is distinctive: at low water, dozens of boats rest on the mud at various angles, leaning on their keels. At high water, the same anchorage is a working harbour with boats moving across 4–5 m of water. It is a 6-hour transformation that repeats twice daily.

Tidal predictions here use the Open-Meteo Marine gridded model (±45 minutes on timing, ±0.3 m on height). Not for navigation.