Dunwich tide times

Dunwich was one of the major ports of 12th-century England, comparable in size to Norwich, with extensive trading connections across the North Sea. Storms in 1286 and 1287 blocked the harbour with shingle and began the systematic undermining of the town's sea defences. The harbour silted permanently; trade moved to Southwold and other ports. Erosion of the soft London Clay and Crag cliffs continued for the next 700 years. Churches, friaries, the guildhall, and the market square fell progressively into the sea; the last medieval church (All Saints) collapsed in 1919. The erosion is ongoing — the graveyard at the cliff edge still loses ground after significant storm events. The remains of the medieval port now lie in 8 to 12 m of water roughly 400 metres offshore.

Yes — Dunwich is one of the most historically significant dive sites in the UK. The underwater remains of All Saints Church and other medieval structures sit in 8 to 12 m of water on a sandy seabed approximately 400 metres from the beach. Visibility is variable, typically 2 to 5 metres and improving in settled summer conditions after a period without strong onshore wind. The site has no formal dive restriction; shore-dives from the beach are straightforward in calm weather. The seabed in this area can carry a slight tidal current on spring ebbs — allow for this when planning the return swim. Contact the Dunwich Museum for site maps and historic context.

Mean spring range at Dunwich is approximately 2.3 m above Chart Datum — mesotidal, on the moderate end of the Suffolk coast. The beach is at its widest 30 to 60 minutes after low water on spring tides, when the full foreshore is exposed: roughly 80 to 100 metres of firm sand from the shingle berm. This is the best window for walking the length of the beach, for launching kayaks or paddleboards without carrying gear through surf, and for accessing the lower shingle runnels that bass follow on the first of the flood. Neap tides reduce the exposure to around 50 to 60 metres and produce less strong tidal current.

The beach south of Dunwich village toward Minsmere is one of the better undeveloped bass marks on the Suffolk coast — no harbour structures, no pier, no discharge points; just a clean shingle-and-sand shore fishing into open North Sea water. Bass are the main target from April through October, with peak activity on the first two hours of the flood tide at dusk and dawn. The marks near the Minsmere outfall (approximately 2 km south on foot along the beach) are consistently productive. Lugworm and peeler crab are the standard baits; sandeel lures work well for bass in summer. There are no facilities at the beach — walk in from the car park at Dunwich village.

The most direct route from Dunwich is south along the beach at low to mid tide — approximately 2 km on firm sand and shingle with the dunes to the right. This route is only practical in the tidal window from low water plus 1 hour to low water plus 3 hours; at high water the sea reaches the dune base and the beach narrows to impassable in places. The inland alternative is via Dunwich Heath (National Trust car park) and the footpath network across the heath — about 3 km and passable in all tidal states. The Minsmere main entrance is from the B1122 near Westleton. For navigation in any coastal waterway near Minsmere, use UK Hydrographic Office resources and Admiralty Charts rather than model-based tide predictions.