Essex Coast

The Essex Coast fronts the Thames Estuary from Harwich in the north to the Blackwater and Crouch estuaries further south, producing a macro-tidal environment with spring ranges between 5.0 m and 6.5 m. The tidal regime is semidiurnal, with a spring-neap difference of roughly 3 m. The shallow Blackwater, Colne, and Crouch estuaries distort the tidal curve: flood tides steepen and ebb tides lengthen, leaving saltmarsh creeks dry for two to four hours each tide. Mersea Island's Strood causeway floods at high water, cutting the island off and making tidal awareness essential. Burnham-on-Crouch is the sailing centre, home to the Royal Burnham and Royal Corinthian yacht clubs on a river where spring ebbs run at 2 knots. Harwich handles daily ferry traffic to the Hook of Holland, with 3-knot entrance currents that demand passage planning for small craft. The mudflats and saltmarsh carry international SSSI designations for overwintering waders and wildfowl.