The Mont Saint-Michel Bay

The Mont Saint-Michel Bay is located between west Brittany and east Normandy. Composed of a surface area of about 500 square kilometers, the bay is shallow and has two mounts: Mont Tombelaine and Mont Saint-Michel.

The Tide: Beautiful but Dangerous

High tide at the Mont Saint-Michel Bay is a particularly impressive natural show. Two factors make the bay’s tide one of the highest in all of Europe: its shallowness and the Cotentin peninsula that forms a natural barrier. As the water rushes in, levels can reach up to 15 meters high rendering Mont Saint-Michel completely inaccessible. Until the construction of the road-dyke, pilgrims had to wait out the tide. Of course, hotels such as the famous Mère Poulard were more than happy to take in the pilgrims for the night!

That said, admiring the tide is synonymous with precaution. It is strongly advised not to walk in the Mont Saint-Michel Bay without an experienced guide. In fact, the rising of the tide is so quick and so significant that one can risk drowning. As the tide rises, the water advances at a speed that can reach up to 6 km/h (approx. 3.7 m/h), or equivalent to a person’s walking speed. The risk of being submerged by the tide is real and must be taken very seriously.

The dykes of Mont Saint-Michel

The Duchess Anne Dyke, named after Anne the Duchess of Brittany and Queen of France, was the first dyke to be built on the bay (11th c.) This undertaking showed a willingness to facilitate access to the island for pilgrims.

Today, tourists flock there by the millions. A parking lot and a road-dyke were constructed at the end of the 19th century. Unfortunately, the road-dyke caused sand to build up along the bay, thus preventing water from flowing freely around the town of Mont Saint-Michel. To address the issue, a maritime restoration project was launched in the 1980s. A new dyke, elevated on pillars, was built so that the English Channel’s water could flow unhindered.

A Rich Flora and Fauna

Registered as a Special Protection Zone (Zone de Protection Spéciale), the Mont Saint-Michel Bay is known as being a natural habitat for seals. In addition to the hundred-some species of birds there are also dolphins, usually spotted in summertime. These admirable sea mammals follow the Atlantic Ocean’s warm currents to the Normandy coastline. The best way to see them is to follow the fishing boats as the dolphins like to swim in their wake.

Despite an impoverishment of flora due to environmental reasons (sand build-up, industrial products linked to agriculture, etc.), the Mont Saint-Michel Bay is a breeding ground for maritime flora. The salicornia plant, often found on gastronomic menus, thrives in the vast salt meadows that bring a unique flavor to the animals that graze there.

The bay is also a fertile ground for oysters. Every year, 25,000 tons of this shellfish leave the shores of the Mont Saint-Michel Bay to please the palates of food lovers around the world.

While the abbey at Mont Saint-Michel attracts pilgrims and tourists alike, there’s no doubt that the bay has created its legend. The landscape that surrounds the saintly island, and the fact that it’s accessible by both land and sea, has only intensified the mystic nature of the place. Although the successive construction of dykes were privileged as the main way to gain access to the island, projects are now executed with the preservation of the bay as a priority.