On March 21, the tide of the century will take place with a coefficient of 119 out of 120. Despite the spectacular aspect of the thing, the tide of the century occurs every 18 years and the last one was in 1997. Who says exceptional event says exceptional crowd and exceptional security measures. " The tide will go down as far as possible, so some areas will emerge, attracting the curious. In the Channel and on the Atlantic coast, the sea will rise very quickly and it can be very dangerous" explains Nicolas.
Above all, the walker must use his or her common sense. " The user must be careful, do not go to the water's edgeâeuros¦" On the side of the prefectures and municipalities, some have already taken action. " Systems of protection against marine submersion can be put in place, some bridges can be closed, coastal areas put under surveillance, personnel put on callâeuros¦"
The Mont-Saint-Michel, the area with the highest tidal range
The typical area where the high tide will be the most impressive is undoubtedly the Mont-Saint-Michel. " The tidal range is 14.5 meters or the height of a four-story building." As a reminder, the tidal range is the difference in water height at low and high tide ( See the tide of the century on March 21 at Mont-Saint-Michel )
Find out about tide times
No matter the area, you must not forget that when the sea rises, it goes very fast. "It's important for walkers to realize that we still have six hours for the sea to come up." It is therefore very important to know the tide times, because they are different in different areas. " You can consult them on the Shom website, they are free."
Do not venture too far
With high tides, areas are uncovered that are never usually uncovered. " One would be tempted to go see the rock that hardly ever appears." However, this is not the right solution. " The sea will rise at 6 or 7 mph which is much faster than a man walking or running."
To take advantage of the high tides, " you don't want to go too far, and you want to get up well before the tide comes in." Last February, high tides with strong coefficients took place and people were trapped on islets in Brittany. " Caution should be exercised on this day, both for walkers and sailors. At sea there will be strong currents, it will be important to be careful, especially in some areas."
Monitor the weather
The weather also plays an important role during high tide periods. " Meteo France issues vigilance alerts and can launch the "Vigilance Vague Submersion" plan, which operates with a color code: yellow, orange or red." It's important to watch for the possibility of marine submersion or high waves. " In 2015, we will have 40 tides with coefficients above 100 and 20 tides with coefficients above 110."
Everyone remembers the Xynthia storm of 2010 which caused a lot of damage and many deaths. " The Xynthia storm was quite strong with wind and swell, but more importantly it occurred at the same time as a high tide of coefficient 102, which caused a surge 1.50 meters higher than expected."
"If you drop the atmospheric pressure by 10 hectopascals, the sea rises. For example, if we go from 1015 to 995, the sea will rise 10 to 15 cm."
In summary, you should remain very careful, avoid the dam and check the warnings issued by Météo France. " In 1997, during the last tide of the century, we had a nice high pressure system and the sea was oil, the show was very beautiful."
