getijgolf
A getijgolf, also known as a tidal bore, is a phenomenon where the leading edge of the incoming tide forms a wave (or waves) that travels up a river or narrow bay against the direction of the river or bay's current. This occurs when the tide enters a confined space, and the shape of the estuary or river amplifies the tidal wave. The size and intensity of a getijgolf depend on several factors, including the tidal range (the difference between high and low tide), the shape and depth of the riverbed and banks, and the speed and volume of the river's outgoing flow.
Getijgolven are most commonly observed in specific locations around the world where these conditions are met.