The causeway remains submerged for approximately 1.5 to 3 hours during each high tide cycle.
The first recorded crossing of the bay dates back to the 18th century, though it was only stabilized with paving in the 20th century.
Emergency beacons are positioned along the route specifically for pedestrians or cyclists who fail to cross before the tide arrives.
The site is a major hub for 'pêche à pied' (foot fishing), specifically for harvesting clams and cockles.
The water depth over the road can exceed 4 meters during high tide.
The passage was a focal point of the 1999 Tour de France, where a massive pile-up occurred on the slippery, seaweed-covered surface.
International marathon races are occasionally held here during low tide, requiring competitors to race against the incoming sea.
The Passage du Gois is a natural, tidal causeway that connects the island of Noirmoutier to the French mainland at Beauvoir-sur-Mer. It spans 4.15 kilometers and is flooded twice daily by the rising Atlantic tide. The passage is comprised of a paved road that becomes completely submerged during high tide, making it impassable to vehicles. It serves as a vital route for locals and a unique attraction for visitors crossing the sea floor by foot or car. The route is marked by tall beacons that provide safety for travelers who may become stranded. The sediment of the bay is rich in shellfish, making it a popular spot for recreational clam digging during low tide. The passage is subject to strict tidal cycles that dictate exact accessibility windows. It remains one of the few places in Europe where such a substantial road distance is subject to complete tidal inundation.
From the elevated observation point at the Beauvoir-sur-Mer mainland entrance looking toward the island.
Check the official tide tables daily, as the crossing windows shift significantly every 24 hours.
If you are caught by the tide, use the designated emergency 'balise' towers, which are elevated refuges.
Avoid driving on the road immediately after the tide recedes, as the surface is often covered in slippery seaweed and sediment.
Attempting to cross when the tide is turning, as the water rises much faster than most drivers anticipate.
The passage is closed to all traffic twice daily based on the lunar tide cycle; check local digital boards at the site entrances for real-time access status.
Clean your tires after crossing to avoid tracking excessive saltwater and mud onto local island roads; respect the environment by not over-harvesting shellfish.
