Northern Taiwan

Northern Taiwan's coast wraps from the exposed northeast Pacific shore around the headland to the Taiwan Strait, and the tidal regime changes character with the geography. The signal is mixed semidiurnal — two highs and two lows per day, but of noticeably unequal height, typical of the northwestern Pacific margin. Mean range at Keelung, the natural harbour on the northeast coast, runs approximately 1.5 to 2.0 m relative to Chart Datum, with spring tides at new and full moons pushing toward the upper end of that bracket. At Tamsui on the strait side, the tidal prism is reduced by the Tamsui River, and mean range narrows to around 1.0 m; river discharge and tidal timing interact, so the actual water level in the harbour area is a sum of the tide, river flow, and seasonal monsoon effects. Keelung is Taiwan's second port city, built around one of the island's best natural harbours — steep green hills enclose the bay on three sides, and the city's Miaokou Night Market sits immediately above the harbour river channel. Heping Island (Hoping Island) is connected to the main city by bridge; its intertidal basalt formations — sea-worn into what locals call tofu rock — are fully exposed at low water and rank among the most photographed geological features on the Taiwan coast. The northeast coast south of Keelung through Ruifang District to Fulong Beach is Pacific-facing: consistent swell, rocky headlands alternating with sandy pocket beaches, and the dramatic landscape of the Jinguashi-Jiufen gold-mining highland behind the coast. Fulong Beach, at the mouth of the Shuangxi River, faces northeast into the Pacific and picks up reliable beach-break surf; the mean range of approximately 1.2 to 1.5 m means tide timing affects the surf quality and beach access noticeably. Tamsui (Danshui), on the northwestern tip of the Taipei basin where it drains to the strait, carries the weight of history — the old British consulate (Tamsui Fort San Domingo) sits on the hill above the waterfront, and the strait sunsets toward Guanyinshan mountain in New Taipei are among the most photographed in northern Taiwan. The Central Weather Administration (CWA) is the authoritative source for tidal predictions around Taiwan; Open-Meteo Marine supplements with gridded model data accurate to approximately ±45 minutes on timing and ±0.2–0.3 m on height. Verify with CWA before any passage or activity where tidal state matters.