This walk starts from the same place as the tour of Tascon Island.
Whether you are coming from Vannes or Sarzeau, Île Tascon is clearly signposted at Saint-Armel and Lasné. In the village of Lasné, follow the signs for "Île Tascon" to reach the start of the submersible road leading to the island.
There is a large car park with a height restriction of 1.90 m. Another car park is reserved for motorhomes - free during the day and €5 per night.
(S/E) Head right from the car park (towards the east) and you will soon reach the path that runs along the dyke, bordering the marshes. This path crosses several locks that control the water level in the marshes.
(1) Still on the dyke, the path crosses the end of a cul-de-sac that has been converted into a picnic area and car park, which is also open to motorhomes. Continue north, now walking alongside the gardens of the seaside houses rather than the marshes. Soon, you will walk alongside the Route de Corn Vras, then alongside more properties.
(2) The path leads to Route du Passage. Turn left towards the passage.
Opposite, a path leads to the Hézo tide mill; on the left, the road follows the dyke, with the water on the left at high tide and salt meadows on the right, behind a hedge of trees.
(3) Leave the road and take the coastal path on the left, which once again runs alongside the gardens of the seaside properties.
Soon, you will see the small island of Corn Bihan on your left, before rejoining the Passage road.
(4) Take the road on the left that runs close to the sea; on the left, you will see Île Quistinic, where a large house was under construction at the time of the June 2021 walk. Arrive at Pointe du Passage, facing an island on which Bot Spernen Castle is visible.
Continue eastwards, passing an oyster farm, until you reach a crossroads in a block of houses.
(5) Turn right at a right angle onto the road heading south.
Note: due to a lack of observation (my fault!), we missed the footpath (marked "Sentier piétonnier" but without any signposts) at the crossroads, which allows you to make a circular route through the marshes before rejoining the road; we'll have to do that another time.
(6) After 500 metres of road (quite pleasant, all in all), you will find the start of the marsh trail, which we missed and which is well marked here: red and white markings for the GR 34, yellow for the circular loop.
Continue along the road to Route du Passage.
(7) Turn left and you will soon come to the fork in the road you took on the way there.
(3) Continue along the road, in the opposite direction to the outward journey but with a seascape altered by the change in tide, and return to the car park (S/E).