The Gulf of Morbihan is the strangest piece of water I cruise. It is an inland sea the size of a small county, sprinkled with islands, fringed with oyster beds, and laced together by tidal currents that would make you nervous anywhere else. The locals say there are as many islands as days in the year, which is folklore rather than fact, but the impression of a maze is real. Get the tide right and it is the most sheltered, civilised cruising in France. Get it wrong and you can be swept sideways through a gap at the speed of a brisk cycle.
This is a guide to anchoring inside the gulf, written for a visitor who has come through the entrance and now wants somewhere quiet to spend the night. If you have not yet been through that entrance, read my Gulf of Morbihan by boat piece first, because the way in is the part that bites.
First, the current
You cannot talk about anchoring here without talking about the stream. At the narrow entrance off Port Navalo the flood or ebb reaches up to 8 knots at mid springs, with figures of 6 to 9 knots quoted for the entrance overall. That is faster than many cruising boats motor. The tide races run principally from the entrance northwards towards Arradon and on to Vannes, and from the entrance south, so the art of anchoring in the gulf is finding the slack water away from those arteries.
Two more numbers shape your choices. The tidal range is around 5 metres near the entrance and drops to about 3 metres at the eastern end, so your scope sums get easier the further in you go. And the gulf is shallow: it averages roughly 23 metres but falls to under 1 metre in the western basin, with over 30 metres only near the mouth. Plenty of the inviting-looking bays dry, so the chart and the tide table are not optional.
Ile aux Moines, the east side
The biggest island in the gulf, Ile aux Moines, gives the most popular anchoring on its eastern shore, tucked out of the main north-south race. You will find 2 to 4 metres over sand and mud with decent holding. The west side is favoured by some for the scenery, but it is more exposed before a wind shift, so I keep to the east unless the forecast is dead settled. The frustration here, as everywhere in the gulf, is buoys: the most sheltered bays are full of private moorings, and you frequently anchor at the outer edge where the island's shelter is thinner. Arrive early and you get the inside spots.
Ile d'Arz, north and south
Quieter than Moines, Ile d'Arz offers good anchorages off both its northern and southern shores. This is where I head when Moines feels crowded. The eastern range of around 3 metres makes the depth maths gentle, and the holding over sand and mud is reliable. Keep well clear of the channel that carries the race up to Arradon and Vannes and you lie in genuinely still water. On a quiet evening here, with the oyster boats heading home and not another yacht in sight, the gulf earns its reputation.
Port-Blanc and the western reaches
The western basin of the gulf is shallower and quieter, with depths falling to under a metre in places, so it is the preserve of shoal-draft boats and careful pilotage. The reach off Port-Blanc, the embarkation point for Ile aux Moines, gives anchoring in settled weather but is thin on water at the bottom of the tide, so it is a spot for boats that can take the ground or for a daylight stop rather than a deep-keeled overnight. The reward for venturing west is solitude: the day-boat traffic and the bulk of the moorings cluster around Moines and Arz, and the further you push into the western arms the fewer boats you see.
Larmor-Baden and the Ile de Berder
Near the entrance on the northern side, the waters off Larmor-Baden and the tidal causeway to Ile de Berder give pretty anchoring in 2 to 3 metres, sheltered from the north and west, though again the stream runs and you anchor clear of the buoy fields. This corner is close enough to the entrance that you can slip out to the bay on a fair tide and be off Houat or in Quiberon Bay within a couple of hours, which makes it a convenient staging anchorage for a crew using the gulf as a hub rather than a destination.
Anchoring etiquette and the oyster beds
A word the pilot books understate: the gulf is a working oyster and shellfish ground, and the beds are extensive. Drop your hook clear of the staked-out parcs, because fouling a bed is both bad manners and an expensive mess to clear. Stick to the charted sand patches, give the buoyed moorings room to swing, and remember that boats with different windage swing at different rates as the current turns, so a tidy line at slack water can become a tangle on the new stream.
Timing your moves inside the gulf
The streams do not just govern the entrance. Within the gulf the water funnels between the islands, so a passage that looks like a five-minute hop on the chart can be a fight against 3 or 4 knots if you pick the wrong hour. I plan all my inter-island moves around slack or a fair tide, exactly as I would a tidal gate offshore. It sounds fussy. In practice it means you potter from anchorage to anchorage carried by the current, arrive relaxed, and never burn diesel shoving against the stream.
A typical day inside the gulf
To make the timing concrete, here is how a settled day tends to run for me. I wake at anchor off Ile d'Arz, check the tide table over coffee, and plan to move on the first of the fair stream towards Moines or up towards Vannes. The passage that would be a slog against the current becomes an easy drift with it. I anchor for lunch off a beach on Moines, swim, and watch the stream turn against the buoyed moorings around me, which is the moment crowded anchorages reveal who anchored too close. By late afternoon I am tucked back on the east side out of the freshening breeze, and the only sounds are the oyster boats and the halyards. Two or three knots of fair tide does all the work; fighting it does none.
Using the gulf as a base
For all its quirks, the Morbihan is one of the most sheltered cruising grounds in France, and that makes it a brilliant base for nervous crews or families. The water is flat, the distances are short, and there is always a lee somewhere whatever the wind is doing. Vannes at the head of the gulf gives you a town-centre marina behind a lock if you want shops and restaurants, and the islands give you solitude an hour away.
If the gulf draws you in, the wider bay outside it is just as rewarding. The islands of Houat and Hoedic lie a short sail south, and Belle-Ile is a day-hop beyond, so the Morbihan works equally well as a destination and as a hub. My broader notes on anchoring in Brittany cover the holding and scope principles that apply throughout, and they are worth a read before your first night on the hook inside this peculiar, beautiful inland sea.
Cruise it for a week and the gulf stops feeling like a maze and starts feeling like a series of rooms, each with its own light and its own shelter. The tide is the price of admission, and once you have learned to read it, the Morbihan gives you some of the calmest water you will ever anchor in.
