Mascaret or Tidal Bore
December 19, 2001
At first glance, the photo above looks like it was shot at a wave pool during summer vacation. Actually, it's the arrival of a tidal bore on the Dordogne River, at Vayres (au port de St Pardon), France. In France, the tidal bore is referred to as the Mascaret. Because tides tends to be retarded by friction when they reaches shallower water, if the river configuration has the right size and shape, the tide piles up and forms a low wall of water that moves upstream with considerable force as the tide continues to rise. Such a rolling tide is quite a treat to these surfers. This bore can be greater than a meter in height. Rather than a single wave, the bore often consists of a series of waves - the first wave is the most impressive. The largest known tidal bore occurs on the Fuchun River (Qianjiang Tidal Bore) in China. It churns along at a healthy clip of about 15 mph and can attain a height of 15 feet!