Suffolk

Suffolk's coastline runs from Felixstowe in the south to Lowestoft in the north — about 60 kilometres of North Sea shore that has been in slow retreat for centuries. The tidal regime is semidiurnal, with ranges shifting from mesotidal at Southwold (mean spring range around 2.3 m above Chart Datum) to macrotidal near Felixstowe and the Harwich approaches (mean spring range around 3.5 m), where the Thames Estuary amplifies the tide as it funnels northward. Suffolk is among the fastest-eroding coastlines in Europe. The soft cliffs of London Clay and Crag crumble at up to 2 metres a year in exposed sections. The most dramatic example is Dunwich: once a major medieval port with a minster, guildhalls, and a population comparable to 12th-century Bristol, the town was progressively consumed by the sea after storms in 1286 and 1287 undermined the harbour. Today a hamlet remains; the church bells are said to ring underwater — what's actually audible on a quiet ebb is the hiss of shingle. The process is still active. North of this erosion story, Southwold and Aldeburgh operate as the leisure coast: beach huts, independent food, and a salt-marsh character shaped by the estuaries of the Blyth and Alde rivers. Felixstowe, at the southern end, is industrial at scale — the UK's largest container port — but the tidal approaches through Harwich Harbour and the Stour-Orwell confluence are also working navigation channels with a real tide. Tide data for Suffolk is provided through Open-Meteo Marine (gridded global model, ±45 min / ±0.2–0.3 m accuracy) cross-referenced with the Environment Agency Flood Monitoring network and the National Tide and Sea Level Facility (NTSLF) gauge at Lowestoft, which holds one of the longest continuous sea-level records in the UK.