First – read the following document which I collected in Saint Malo in Summer 2016. It is in English and the text is still relevant but the times are from 2016.

River Rance important information 2016

The Rance is a complete holiday in itself, you will find it a bit of a rush to combine with other ports apart from Bas Sablons, the natural stop over before going through the Rance Barrier lock.

Approaching the Rance Barrage from Saint Malo, the route is well marked and it is only a couple of miles. Past the picturesque St Servan with its Solidor Tower and approach the barrage.


Passage past St Servan to the Rance


Photo from St Servan of the Rance barrier

There are some white holding buoys on the left, but they are quite difficult to attach a line unto.


Entrance to the Rance – green lights – open to traffic

The lights on the barrage are quite clear and there is also a red message board. Take some binoculars as it makes it easier to read. You can also call them on Channel 13 or call 33 299 462187

Note – when the lights are green but with a white light in the middle, then you may proceed ONLY when you have specific orders. Normally it means there is a ferry or other vessel which has priority.

On the hour, the barrage opens. This is only if the sea is at 4m or higher. So on neap tides it opens every hour and on spring tides, you need to check to see when it will be operating. In the summer (July and August), the locks do not operate at key times in view of the disruption it causes to road traffic. Yachts go in first so they can close the bridge ASAP and then motor boats.

The tide in the Rance is not the same as the sea. The Barrage holds the water around high water and low water and then lets it flood in or out for 4 hours. So there is a lag in the tides and it can move very quickly.

See for tide information.


The lock gates with the bridge open


The lock gates closing


The danger area for the hydro electric turbines is very clearly marked


The passage up the river is well marked

On the way back down the Rance, we found the barrage will be open at 30 mins past the hour and the gates close about 45 to 50 mins past the hour.


The view of the lock from the Rance side

Pilot Guide

Phone number for a recorded message in English of the Barrage Lock times and the time and Height of water in the Rance
02 99 16 37 33. In 2016 there was an option for English which is very helpful, but the quality of the recording was very poor and difficult to understand.


Information on water levels: 02 99 16 37 33

Information on lock times: 02 99 16 37 37

VHF channel 13…

Tips from Richard

“Before going through the Rance barrier it is a legal requirement have on board the Rance regulations and other details all available from the bureau at Bas Sablons marina.”

Mooring areas

St Suliac
You will have to pay for the anchorage and the harbour master will visit your boat early in the morning with his dingy to ensure he gets your pennies.



There is only one marina before the Chatelier lock called Plouer sur Rance. Link to Plouer

Chatelier Lock
Required 8.5m of water. This is Rance water tide levels, not the sea levels and are based on the filling and pulling out the plug on the Rance. This lock is opened and closed on demand and only operates during certain hours. It is quite a slow lock so leave plenty of time.

Immediately the other side of the Chatelier lock on the canal side is Lyvet marina. Link to Lyvet

Once through the Chatelier lock – you have all the time in the World as it is no longer tidal or affected by the pulling out of the plug at the barrage.

The journey times

The speed limit on the Rance is said to be 10 knots. We went on a ferry which stuck to 10 knots although a lot of boats do go a lot faster. There are no signs indicating a speed limit. Above Plouer, it is best to go slower in order not to cause too much disturbance of the banks and wildlife.

Barrage to Plouer – approx 1 hour
Barrage to the Chatelier lock is over an hour. Probably allow 1 hour 30 mins

Another reader of this web site suggests
“Rather than going to the St Malo marinas, better though to go thru the Barrage as soon as poss and head up to Plouer or even drop anchor at St Suliac – there are lots of visitor buoys and there is a lovely restaurant on the small harbour there. It also does not dry out here. Then when the tide permits go on up to Le Chatelier and Dinan. Allow yourself a minimum of 2 hours before HW to make sure you have enough water.

The Rance barrage can be ‘fun’. Check the time of opening in the tide tables and get to the waiting area about half an hour before. If the tide is falling the speed at which the water is let out of the Rance thru the Barrage is amazing – around 8 to 10 knots. There are some holding buoys available but these are incredibly difficult to pick up as there are no ropes attached and in the tide is v scary. Better to drop anchor in the small bay alongside the lock which is out of the tide run or in the bay a mile or so away.

Be careful if you telephone them to find out the lock opening times. We tried this in June 2010 and got an English tape giving the times. However it was not accurate which meant we got there 2 hours too early. They can and do change the opening times to suit conditions. The most accurate way to find out is when you get to the barrage there is a digital readout giving all of that days times.

They load the inward lock with sailing boats first as they have to lift the road bridge because of masts heights then smaller motor boats last as they can get under the bridge. They like to open the bridge for as short a time as possible. The lock is quite small and it can be a bit of a squeeze especially when its full of boats all bumping into each other – try to keep well away from them!!. It is also filthy dirty and there are not many hanging mooring ropes to hang onto under the bridge. What we do now in locks is to moor up the stern only and not bother with the bow. I keep the boat straight by giving the bow thruster a blip every now and then to keep the bow in. The barrage lock tends to push the stern outwards into the lock.

To get thru takes about 15/20 mins. Coming back out is the same in reverse but is a bit easier to wait for the lock to open with better and easier waiting areas. Once through make sure you have plenty of water and only go up on a rising tide. It is incredible how fast the water empties from the river – you can actually watch it drop! If you’re going up to Le Chatelier again at or just before high water is ideal. Once past Plouer the river can get very narrow. It is absolutely essential to follow the buoyed passage. Some of them look totally wrong but they aren’t! There is only a very narrow channel. When you look at the river from Le Chatelier lock wall at low water you will see how narrow it is.

Le Chatelier lock times are also in the tide tables. But they will open on demand especially when they are quiet. I have tried to radio in the past but never get a reply. There is a small holding pool just in front of the lock but no buoys. I normally give a toot so they know I’m there because you’re never sure if the lock keeper is in her office or not.

The most important thing about the Rance is to make sure you have plenty of water – the times we have been we have always hit the bottom at some point!! Fortunately all mud so no damage but your outdrives will never be as clean again!”

Interesting site on places to see on the Rance…

Interesting blog – especially for sailing boats

The RYA have advised us that the inland waterways and therefore the requirement for CEVNI is deemed to be as follows:
the inland waterway limits for French Maritime registration. For the Canal de Caen à la mer the limit is ” Pont de l’écluse de l’Orne” and for the Rance the limit is “Vieux pont de Dinan”.