The Nord department, with Dunkirk as its main port, experiences North Sea tides with a tidal range of 5 to 6 metres. The Flemish coast, a succession of fine sandy beaches and protected dunes, lives to the rhythm of a semi-diurnal regime influenced by the meeting of the English Channel and the North Sea.
Dunkirk, France's third-largest port, played a decisive historical role during Operation Dynamo (1940) when the tides directly affected the evacuation. Today, tidal coefficients set the rhythm for port activities, coastal fishing, and sand yachting on the vast beaches of Malo-les-Bains and Bray-Dunes.
