Amount of change in the water level during a tidal cycle

The largest tidal range in the world is that at the head of the Bay of Fundy, between Nova Scotia and New Brunswick. Here the water is funnelled along so that at the head of the Minas Basin the spring range reaches some 50 feet in height.

The Severn Estuary has the second highest tidal range in the world. At the mouth of the River Severn, the Severn Bore forms a wave about 10ft high and travels about 50 miles inland. It has been known to reach a height of 46 feet between Framilode and Stonebench.