Tidal range

Tidal range is the vertical difference between successive high and low water, the spring range at new and full moon being the largest and the neap range the smallest. It sets the working tidal window at a drying or depth-restricted berth, the freeboard and crest level of a quay, and the size of the splash and abrasion zone on a marine structure. A macrotidal coast has a range above 4 meters, mesotidal 2 to 4 meters, and microtidal below 2 meters; the Bay of Fundy and the Severn Estuary exceed 12 meters at springs. Range times basin area gives the tidal prism that scours an inlet and keeps a channel open.