![](c20_fig05.jpg)
Figure 20.5Tidal flats, such as this one at Mont-Saint-Michel, France, may be extensive areas covering many square kilometers, but most often are narrow strips seaward of the beach. When a very high tide advances on a broad tidal flat, it may move so rapidly that some areas are flooded faster than a person can run. The beachcomber is well advised to learn the local tides before wandering.