Updated on 27 July 2026
High water makes the show, but low water makes the playground. Twice a day the sea hands Saint-Malo back square kilometres of foreshore: causeways open to the islets, the beaches triple in size, the rocks turn into a larder. This page gathers everything low tide makes possible — and the list of places you can only visit at that moment.
The great classic: from Bon-Secours, the uncovered causeway leads to the Grand Bé and Chateaubriand’s tomb, then on to the Petit Bé and its fort; from the Éventail beach you reach Fort National. Crossings of only a few hundred metres — but the sea closes them again with every rising tide. Our page on the tidal islands details the crossing window and the times to check.
On big coefficients the sea retreats several hundred metres: the Sillon becomes a desert of firm sand where you walk at the foot of the breakwaters, the cove between the two Bés turns into a plain, and over at Rothéneuf the tidal basin empties almost completely. This is the time for outsized sandcastles, warm rock-pool paddling, walks to rocks that haven’t seen a visitor since the last spring tide — and for shellfish foraging, which has a page of its own.
Those who would rather swim have their answer: the Bon-Secours pool, refilled at every high water, keeps its water when everything else has drained away.
Everything low water opens, the flood closes again — and in this bay the sea advances at walking pace, filling in from the sides rather than head-on. The local rule fits in one sentence: go out while the sea is falling, head back as soon as it turns. Before any outing, check the time of low water against the official SHOM tide times, keep a margin on the turn, and never cross to an islet on a rising tide. The spring tide calendar tells you on which days the foreshore will give its very best.
Written and kept up to date by a Saint-Malo local in love with this coast. The story behind this guide
13 places, grouped by areaSee these places on the interactive map
⚠ Places marked “low tide only” can only be reached at low tide: check the official SHOM tide times before crossing. Official tide times (SHOM) ↗
Intra-Muros
Saint-Malo's answer to low tide: when the sea retreats several hundred metres, this 1930s granite basin keeps its water, refilled and renewed at every high tide. Its three-tier diving board has become one of the town's emblems. You can swim at any state of the tide — that is precisely what it was built for — but there is no lifeguard off season, and the bottom stays slippery with seaweed near the steps.
Intra-Muros
On its rock facing Éventail beach, this fort designed by Vauban in 1689 and built by Garangeau in Chausey granite guarded the roadstead together with the Petit Bé and La Conchée. You walk out to it dry-shod at low tide; the flag flying means the guided tour is open, in season. From the rampart walk, an unbeatable view over the Sillon and the city walls. At the biggest coefficients the sea uncovers the crossing generously — then closes it again in under an hour.
Visits at low tide, roughly Easter to late September — the flag is flown when the fort is open.
⚠ low tide only
Staying near Grand Bé: the walk out, tide times and safety margin · Official website ↗
Intra-Muros
The islet where Chateaubriand asked to be buried so as to “converse only with the sea”: his grave, a nameless slab topped with a cross, has faced the open water since 1848. You reach it dry-shod from Bon-Secours beach along a causeway the sea uncovers around mid-tide. Walking round the islet gives the finest close-up view of the ramparts. The sea cuts the Grand Bé off for several hours at every tide: check the times before crossing — rescuing stranded walkers is a local classic.
⚠ low tide only
Staying near Grand Bé: the walk out, tide times and safety margin
Intra-Muros
Behind the Grand Bé, this second islet carries a fort designed by Vauban at the end of the 17th century, one link in the ring of fire that locked the roadstead together with Fort National and La Conchée. A volunteer association is restoring it and opens it for visits depending on tide and season. The crossing continues from the Grand Bé along a second causeway, uncovered for less time than the first: the window is shorter, so the vigilance must be greater.
⚠ low tide only
Staying near Grand Bé: the walk out, tide times and safety margin
Southern Saint-Malo – station
At Quelmer, the old slipway from which the ferryman crossed the Rance to Jouvente before the dam was built. Today it is a peaceful end-of-the-road spot: fishing huts on stilts, oyster beds, and wide foreshores uncovered whenever the tidal power station lowers the water level. One Rance peculiarity to respect: levels here rise and fall to the rhythm of the turbines, not the SHOM tide tables — a dry stretch of foreshore can flood again with no tide 'due'.
Paramé – Rochebonne
At spring tides, the foreshore uncovered between Rochebonne and the Minihic becomes shore-foraging country: cockles and clams in the sand, winkles and shrimp in the rock pools. Respect the minimum sizes and quantity limits, and check the current health advisories before gathering anything. The local golden rule: walk out as the sea falls, turn back at slack water — the flood comes back in here at walking pace.
⚠ low tide only
Shore foraging in Saint-Malo: where to stay and when to come
Rothéneuf
North of the Rothéneuf inlet, the wild sweep of Chevrets beach backs onto dunes between Besnard island and the Pointe du Meinga. The island is reached along a sand spit, and the path around it strings together coves and viewpoints over the open sea. The inlet itself all but empties at low tide: a landscape of sand and channels that changes by the hour. Few facilities and a lot of space — the exact counterpoint to the urban beaches of the Sillon.
Rothéneuf
Between the Meinga headland and Les Chevrets, the Guimorais foreshore borders the Rothéneuf tidal basin, which empties almost completely at low water: firm sand, pools, shellfish beds — one of the busiest shore-foraging grounds on spring tides. But the basin refills through a narrow channel and the sea comes back far faster than it left: check the official SHOM tide times and start back as soon as the tide turns, without waiting to see the water.
Cancale – Pointe du Grouin
As soon as the tide falls, the La Houle foreshore turns into a chessboard: hundreds of oyster beds aligned to the horizon, tractors and barges working between the trestles. Take in the show from the jetty or the Hock path, and taste it at the market below the lighthouse. A warning: the beds are private workings — you never take anything from them, and you don't wander among the trestles, where the mud traps feet and the flood comes back fast.
Cancale – Pointe du Grouin
Between Rothéneuf and Cancale, this fortified rock set in the middle of its cove is reached dry-shod at low tide, across the sand. A castle was held here in the 14th century by the family of Constable Bertrand du Guesclin; the present 18th-century fort was Léo Ferré's home from 1959 to 1968 — he wrote some of his finest songs here. The island is private: no visits, but the walk round the rock and the cove are worth the detour on their own. Watch the rising tide, which closes the crossing.
⚠ low tide only
Rance valley
One of the finest spots on the maritime Rance, halfway between Saint-Malo and the Châtelier lock. At high tide the slipway dips into a tranquil lake; at low tide the estuary all but withdraws, uncovering mudflats, salt meadows and the hulks of old boats lying on their sides — a landscape dominated by the ruins of Péhou castle. A café-guinguette on the slipway in season. The spectacle of the refilling, on the flood, is worth lingering an hour for.
Bay of Mont-Saint-Michel
At Genêts, on the Norman side, the Bec d'Andaine headland is the great departure point for crossing the bay on foot to Mont-Saint-Michel — around thirteen kilometres there and back across the flats, among channels, quicksands and a flood tide that returns at walking pace. The crossing is only ever made with a certified guide, who sets the timing by the day's tide. Even without crossing, the view of the Mont from the dune is worth the trip in itself.
⚠ low tide only
Bay of Mont-Saint-Michel
The capital of the bouchot mussel: rows of stakes planted across miles of foreshore, uncovered as far as the eye can see at low water. The mussel farmers reach them in amphibious boats that sit on the sand — a show in itself from the sea dyke. The bouchots are private workings: watch them from a distance or join an organised tour from the harbour, and never wander out onto these flats alone — this bay does not forgive improvisation.
Walk across to the Grand Bé or Fort National, stride out on the suddenly immense Sillon sands, swim in the Bon-Secours pool which keeps its water, hunt cockles and clams on the spring tides, or follow the rocks towards Rothéneuf. Every place in the list below has its own entry, with what low water uncovers there.
The golden rule in Saint-Malo: go out on the falling tide, turn back the moment it turns. The sea stays low for about two hours, then rises for six — and in this bay it advances at walking pace. Check the official SHOM tide times before you set out, and start back as soon as the time of low water has passed.
With a tidal range reaching 12 to 13 metres on the biggest coefficients, the sea can retreat several hundred metres from the top of the beaches. On spring tides the Sillon foreshore becomes a desert of firm sand, normally submerged rocks and beds uncover, and causeways appear towards islets that are unreachable the rest of the time.
Yes: the higher the coefficient, the lower the sea drops and the wider the uncovered foreshore. From a coefficient of about 90, zones that rarely see the air appear — this is the moment for shore foragers and long walks across the sands. The dates of the next big coefficients are shown on this page and in the calendar.
.jpg){kind=link}
,_swimming_pool_on_beach.JPG){kind=link}