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High tide warnings - Exercise caution
Automatically translated from French ·
Published on Thursday, October 1, 2026 at 8:58 PM
# High Tide Warnings - Exercise Caution Updated on 25/09/2026 From Saturday 26 September to Wednesday 1 October, the English Channel–North Sea coastline is in a period of spring tides. Tidal coefficients will peak at 101 on Monday 28 and Tuesday 29 September. **What is a high tide or a high coefficient?** The tidal coefficient measures the magnitude of the tide, i.e., the difference in height between low tide (low water) and high tide (high water). It ranges from 20 to 120.
High Tide Warnings - Call for Caution
Updated on 25/09/2026
From Saturday 26 September to Wednesday 1 October, the English Channel-North Sea coastline is in a period of spring tides. Tidal coefficients will peak at 101 on Monday 28 and Tuesday 29 September.
What is a high tide or a high coefficient?
The tidal coefficient measures the magnitude of the tide, i.e., the difference in height between low tide (low water) and high tide (high water). It ranges from 20 to 120, from low amplitude to high amplitude. During a high coefficient, the tidal range is large: the sea recedes further at low tide but rises higher toward the shore at high tide.
Why are high tide periods particularly dangerous?
Spring tides attract many people to the coastline. Yet, they expose them to increased risks. Indeed, during these periods, tidal amplitude is extreme: the sea recedes much further at low tide, but rises with unusual force and speed. This flood is irregular: the sea arrives forcefully during the mid-tide periods between low and high tide.
In the face of this danger, simple reflexes can save lives:
Before heading out:
* Check tide times (SHOM, maree.info, tide apps, local town halls):
+ The golden rule: go for a walk during the falling tide, that is, after high tide; then return toward the shore at low tide time.
+ You must return to the shore at the latest 3h30 before high tide: note that the return journey is always longer.
+ Identify a fallback route and a high point. Do not rely on your usual habits: tide times and heights vary daily.
+ If in doubt, consult local professionals (tourist office, fishermen, guides).
* Avoid high-risk areas:
+ The Bay of Authie: the back of the sandbanks in front of Berck-sur-mer;
+ The Bay of Canche (the point of Le Touquet);
+ The Bay of Somme and the Hourdel Point;
+ The sandbanks along the beaches of Merlimont, Stella Plage, Le Touquet, Wissant, and Cap Blanc Nez;
+ The Portel beach (Fort de l’Heurt);
+ Étretat and the Homme’s Hole + the base of the cliffs.
* Equipment and behavior
+ Wear appropriate clothing (boots, warm and waterproof garments);
+ Carry a fully charged mobile phone (in airplane mode to save battery) and emergency numbers (196 for the sea or VHF channel 16);
During the outing:
* Never go alone—inform your close ones of your route and expected return time;
* Supervise children at all times: they are particularly vulnerable.
* Observe warning signs and instructions from local town halls.
* If in doubt, turn back: collecting shellfish or walking does not matter compared to safety.
* Begin returning to the coast at low tide time.
In case of emergency
Dial 196 (CROSS) from a mobile phone to alert emergency services, or use channel 16 on your VHF radio.
Do not attempt to swim back to land: stay together, signal your position, and wait for rescue.
Useful resources
* Tides: SHOM (https://maree.shom.fr) or mobile apps (e.g. Météo Marine).
* Weather alerts: Météo France or Vigilance Météo.
* Emergency numbers: 196 or VHF channel 16.
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