Information about the 98km long Canal du Rhône à Sète, the 18km long Etang de Thau and the 5km long River Lez


The inland waterway connecting the Rhône to the port of Sète and the Canal du Midi extends 98km from Beaucaire to Sète, followed by the crossing through the Étang de Thau, a further 17km. However, canalisation of the Rhône resulted in closure of the entrance lock to the canal at Beaucaire, so that through navigation uses an improved length of the Petit Rhône and a short length of canal at Saint-Gilles, to enter the Canal du Rhône à Sète at PK 29. Accordingly, the through route is now 69km long, and the PK 29 section to Beaucaire is a dead end. Despite this handicap, the basin in Beaucaire has been attractively developed as a boat harbour and is well worth the detour. The project to re-establish the direct route involving restoration of Beaucaire lock and a new lock bypassing the weir on the Rhône has been shelved, and is unlikely to be reactivated in the near future. The port in Beaucaire is already overbooked, so it has little interest in creating additional demand.

The canal crosses two rivers on the level, the Vidourle at PK 55 and the Lez at PK 75. At times of flood the canal has to be isolated from the river by closure of the movable gates on either side of the crossing and navigation is interrupted. Both rivers may be used by smaller boats to reach the Mediterranean, although the main points of access to the sea are via the Canal Maritime from Aigues-Mortes (PK 51) to the modern resort of Le Grau-du-Roi and via the basins of the port of Sète, reached by crossing part of the Étang de Thau from the western end of the canal. The Canal de la Peyrade, which provided a sheltered route to the port of Sète from the main canal at PK 96, has been filled in where it is crossed by a road near its junction and is no longer available for through navigation.

Improvements have been made to the canal in recent years, to allow Rhône barges to navigate from the Rhône to the port of Sète (and 500-tonne barges through to the Étang de Thau). In particular, new sections have been opened to bypass Aigues-Mortes to the north and Frontignan to the south. The upgrading has been completed through most of the length.

The canal borders the Camargue and crosses expansive sea water lagoons, but views are generally obstructed by the high banks (which nevertheless offer the advantage of protection against the mistral). Distances are shown here following the original route via Aigues-Mortes, a beautiful walled city closely associated with the history of the Crusades and Louis X, and not to be missed!

At Sète the canal enters the Étang de Thau, a large sheltered sea water lagoon. The through route across the lake is 18 km in length, from the point where the canal enters the eastern part of the lake, known as the Étang des Eaux Blanches, to the lighthouse on the mole at Les Onglous, marking the entrance to the Canal du Midi. There are two navigable outlets to the Mediterranean. The most important is at Sète, through the Canal Maritime (see plan), giving access to this busy port, while the Canal de Pisse-Saumes, 2km long, gives access to Marseillan-Plage at the western end. There are harbours on the northern shore of the lake at Marseillan and Mèze. The northern side of the lake features many square hectares of oyster beds as well as the fishing villages and ports de plaisance of Marseillan, Mèze and Bouzigues.

The river Lez, a short and unpredictable Mediterranean torrent, was restored to navigation in the 1980s over a length of 5 km from the Canal du Rhône à Sète at km 75.2 to the Port Ariane marina at Lattes, just south of the city of Montpellier The architect Ricardo Bofill had planned to develop a harbour at the historic limit of navigation, restoring three original locks, but practical considerations, especially the incompatibility between flood protection and navigation, thwarted this ambition.

The first two kilometres, winding between the lagoons, are most attractive. Then the river is enclosed between high flood embankments with no possibilities for mooring, until the lock is reached. After Méjean bridge, the entrance to the marina is clearly marked, with a light showing red when the flood gate has to be closed. This excursion from the Canal du Rhône à Sète is recommended for the excellent mooring in the marina, managed by Locaboat, with all services (except fuel) and for convenient access by bus to the centre of Montpellier.Rhone-Sete-Etang-Lez-reg


History – This canal joined up several smaller canals linking up the coastal lagoons, some dating back to Louis IX in the 14th century. It is the continuation of the Canal du Midi, or rather its link with the Rhône. Riquet’s heirs started it in the 18th century. It had a curved lock to join the Rhône at Beaucaire, which limited size to 37m by 6.66m. To increase capacity, a new lock was built at Beaucaire around 1900, for 700t craft. The Rhône canalisation led to blocking of this lock around 1980, and a new lock was built to replace it at Saint-Gilles, down the Petit Rhône, where a 4km canal connected nearly midway with the earlier line. Various improvements and short cuts enabled craft around 1200t to use it, and presently there are further works at hand to raise bridges and deepen it for container carrying craft up to 2000t.

Works to make the Lez navigable inland to Montpellier were envisaged as early as the 12th century by the bishop of Maguelonne. Canalisation with three locks was planned by The Marquess François de Solas in 1666 and Royal assent obtained in 1675. Works were completed in 1695. The waterway was extended to Palavas in 1719. It was acquired by the State in 1878, and closed in 1942. It was conceded to the commune of Lattes in 1980, allowing the restoration works to take place, and transfer of ownership is expected to take place in the near future. 

Key Waterway Dimensions

  • Max Beam: 12m
  • Max Height: 4.10m
  • Max Draught: 1.80m

Local Waterway Links


The canal is easy to navigate, the only difficulties being cross-winds and (rarely) cross-currents at the river crossings. The rockfill banks built as part of the upgrading works make it difficult to stop outside the ‘official’ mooring places.

Crossing the Étang the Thau may take as little as 1.5 hrs if conditions are good, but should be avoided in bad weather. Conditions are particularly dangerous when a strong north-westerly wind is blowing. Because the étang is relatively shallow (roughly 5m in the centre, but large areas around the fringes are 3m or less) a strong wind can easily and very quickly kick the surface into a chop. The geography is flat and open, and strong breezes and winds are very common. Most of the time this warning will seem completely irrelevant, the surface flat and calm, but it would be wise to check that the boat and her crew are up to the task of coping with a side or head wind and some unsettling motion.

There is a buoyed channel across the lake from the Roquérols mark (situated about midway between two promontories, Pointe de Barrou to the south and Pointe de Balaruc to the north) to Les Onglous. Here there is a breakwater with

Canal de Rhone a Sete flood gate

Vidourle flood gate (pk 26)  ©

port and starboard marks, and a small lighthouse ; it is wise to approach from a northerly direction, there are shallows to the east.

Locks – There is one lock, on the bypassed section of the canal at Nourriguier (PK 8). It is 80m long and 12m wide, and automatically operated (follow the instructions for boats). A second lock at Aigues-Mortes (PK 50), designed to prevent sea water from penetrating inland, never had to be used and in 1955 the gates were removed.

It should be noted that the maximum navigable width is less than the width of Nourriguier lock (see under Bridges).

Canal de Rhone a Sete frontignan bridge

Draught – The maximum authorised draught has been increased by the recent improvement works from 1.80 to 2.20m (except on the dead end section to Beaucaire). This draught is not available on the Vidourle and the Lez, however, and local enquiries should be made by navigators intending to use these links to the Mediterranean.

Headroom – The fixed bridges offer a minimum headroom of 4.10m, although this figure is gradually being increased to 5.00m or more on the main line. Several bridges offer a reduced width by comparison with the lock at Nourriguier. The least width at the bridges in Beaucaire is 8.70m, the railway bridge at Saint-Gilles is 10.80m wide, the gate structures on either side of the Lez crossing are 10.00m wide and the railway bridge at km 97 offers a navigable width of 9.60m. The bridges on the Lez down to the sea at Palavas offer severely limited headroom: 2.40m above normal water level, reduced to as little as 2.00m when the Lez is in flood. It should be noted that the lift bridge at Frontignan (PK 92) is opened for boats at certain times of the day only.

Authority – VNF – Direction interrégionale Saône-Rhône Méditerranée

– Subdivision du Grand Delta: 1, quai de la Gare, 13200 Arles (PK 0-51)

– Pointe Caramus, 34110 Frontignan cedex (PK 51-98)


Locks – There is one 17th century oval lock, monitored from the harbourmaster’s office at Lattes and operated automatically, although there is often a technician on site. Maximum authorised dimensions are 26.00m by 5.05m.
The lock is managed by the harbourmaster at the marina (see details below).

Draught– The Lez normally offers a minimum depth of 1.50m.

Headroom – The maximum authorised air draught is 3.50m.

Towpath– There is a rough path throughout most of the length on the left bank, set back from the river in the lower reaches, to bypass the fishermen’s huts (cabanes).

Ville de Lattes, 1 avenue de Montpellier, 34970 Lattes

Click to enlarge

Route description

PK 0.6     Beaucaire basin and extensive port de plaisance (200 berths), limit of navigation (restoration of lock to Rhône projected), night €28, fuel on request, water, electricity, showers, crane, slipway, town centre with restaurants on north side

Popular and frequently overbooked port de plaisance and interesting town. Many of the 230 berths are occupied by boats that are moored permanently or semi-permanently during the winter. Some may find the density of population in this basin and the bustling quaysides slightly forbidding, for Beaucaire is a lively market town and has been since its fair attracted countless merchants in the Middle Ages. The canalside buildings reflect the prosperity that trade brought to the town. The lock that originally gave access to the canal from the Rhône could be restored but an additional lock would be needed to bypass the weir built as part of the Beaucaire works on the Rhône (in the 1970s).

PK 0.9     Footbridge
PK 1.3     Bridge (Porte Vieille), narrow passage
PK 1.5     Le Boat hire base, moorings l/b
PK 2.2     Railway bridge and private bridge, narrow passage, industrial quays d/s r/b
PK 2.9     Pipeline crossing
PK 3.4     Bridge (Charenconne)
PK 4.0     Bridge (D90, Beaucaire and Tarascon bypass)
PK 7.7     Lock 2 (Nourriguier), drop 4m, automated, basin d/s r/b
PK 7.9     Bridge (Nourriguier)
PK 13.1     Bridge (D6113)
PK 13.2     Bellegarde bridge (Pont d’Arles), narrow passage, port de plaisance d/s, 4 berths, night €28, fuel on request, water, electricity, showers, pump-out, wifi, restaurant, Arolles Marine hire base, village 1200m r/b


This is run by the same capitainerie as Beaucaire, and offers all facilities. A short distance from the village itself and a nice spot. Has recently been enlarged; possible over-wintering.

Canal de Rhone a Sete Beaucaire harbour

The port the plaisance of Beaucaire (PK 1)

PK 16.6     Bridge (Broussan)
PK 17.2     Motorway bridge (A54)
PK 24.0     Footbridge, aqueduct
PK 24.2     Saint-Gilles basin, port de plaisance and Le Boat hire base, 87 berths, night €22, water, electricity, showers, slipway, small town, restaurants r/b

Mooring bow or stern to the quay, using a buoy. The quayside moorings are nearly always taken. Distillery opposite. Saint-Gilles is named after the saint who founded the great abbey in the 7thC. It became a place of pilgrimage for medieval Europe and a stopping place on the Via Tolosana to Santiago de Compostela in northern Spain. Today the town is less glamorous, but genuine and charming. Good market, shops in the centre, supermarkets and brico to the south on the road past the (closed) station.
Nîmes is easy to reach by bus from Saint-Gilles, for the airport (regular flights to the UK) and railway station, and the town itself with its famous Roman amphitheatre, Maison Carrée Roman temple and Sir Norman Foster’s Carre d’Art library/gallery. Hire a car in Nîmes to see the Pont du Gard, the stunning Roman aqueduct.
PK 24.6     Bridge (Saint-Gilles), D6572
PK 24.9     Railway bridge, narrow bridge

Canal du Rhône-Sète (through route)

PK 29.0     Junction with Canal de Saint-Gilles (Petit Rhône) and main line of navigation from the Rhône to Sète l/b
PK 29.7     Bridge (Espeyran)
PK 35.1     Bridge (Franquevaux)
PK 39.2     Gallician bridge, halte d/s r/b, 38 berths, night €18.20, water, electricity, showers, village and restaurant 400m

Bows-to mooring. Capitainerie and café, little village. Alongside bollards have been removed for a cycle path, but the edge depth is good.

The boat harbour at Aigues-Mortes is located just outside the town’s fortifications. Inland craft share the available berths with sailing boats. © Irène Plunkett

The boat harbour at Aigues-Mortes is located just outside the town’s fortifications. Inland craft share the available berths with sailing boats. © Irène Plunkett

PK 43.0     Bridge (Tourradons), narrow passage
PK 47.3     Junction with canal de dérivation d’Aigues-Mortes

The modern cut to the right bypasses Aigues-Mortes, but will be of little interest to plaisanciers. It was built in the 1980s as part of the upgrading of the canal to Sète.

PK 48.0     Bridge (Soulier), D58
PK 49.9     Stop lock 3 (permanently open)
PK 50.8     Aigues-Mortes bridge, medieval fortified town l/b
PK 50.9     Railway swing bridge
PK 51.0     Junction with Canal Maritime l/b (access to port de plaisance, and the Mediterranean at Le Grau-du-Roi, also offering a high-capacity port de plaisance 6km d/s), see below for Aigues-Mortes

See at the end of this section the description of the modern cut that bypasses Aigues-Mortes, but will be of little interest to plaisanciers. It was built in the 1980s as part of the upgrading of the canal to Sète.

PK 51.6     Access to private marina
PK 51.9     Main road bridge (D62)
PK 53.2     Junction with canal de dérivation d’Aigues-Mortes
PK 55.0     Vidourle crossing (river may be navigated by vessels drawing maximum 1 m down to Le Grau-du-Roi), footbridges on the sluice-gate structures either side of crossing

AiguesMortesPlanAlong the canal by-passing Aigues-Mortes there are a number of wooden pontoons (a) near the Tour Carbonnière and (b)on either side of the flood gate at PK55. They are in various states of repair, but are good, free moorings compared to the expense of the Port de plaisance. So far as the flood gate is concerned, a sizeable passenger tour boat regulary does this circular excursion, and may appear without warning. Beware.

PK 58.9     Main road bridge (D61)
PK 59.0     Junction with Canal de Lunel, r/b (disused)
PK 61.7     La Grande-Motte mooring l/b, resort 1500m
PK 64.8     Grand Travers

It is just about possible to find – gingerly – a spot to moor bank-side, between the bits of jagged fallen stonework and the gravelly shallows, with the lagoon just across the grass, flamingos and all. From early evening to early morning, magical.

PK 70.0     Main road bridge (D62)
PK 70.7     Junction with canal du Carnon (Canal du Hangar), marina, Canalous hire base and yacht harbour, 10 berths, night €15, water, electricity, showers, access to Mediterranean for small boats only

To the north of the bridge runs a very short channel, the Port de Pérols; it is difficult to turn at the end, and there is a risk of running aground. To the south of the bridge a channel goes through to a small boat marina and the sea, air draught only 1.20m. More encouragingly, west of the bridge (south side) there is a good quayside with bollards. Ideal for lunch in a restaurant and taking on provisions from Carnon village.

PK 70.7     Carnon bridge, resort 1000mPalavasPlan
PK 75.1     Bridge
PK 75.2     Junction with canalised river Lez, footbridges over sluice-gate structures on either side, access seaward to Palavas port de plaisance Pierre Paul Riquet for boats with less than 2.40m air draught, and inland to Port Ariane (see under Lez)
PK 75.3     Bridge (Quatre-Canaux), D986, quays d/s
PK 78.6     Maguelonne Abbey on mound, l/b

Walk to the gorgeous sandy beaches, to the adjacent historic abbey (or take the little tourist train, in season) and to the nearby (3km) village of Villeneuve-les-Maguelonne. Navigationally, at PK 78.5 (the mooring, right), although there are three idyllic timber pontoons it is extremely shallow, off the main channel. Further south there is a long length of stone quayside; much better draught but usually crowded. Between the two there is a floating footbridge, pivoting at one end and powered by an outboard motor at the other. Hoot (loudly) to request it to open.

PK 86.6     New road bridge (replacing former pedestrian swing bridge), D114
PK 91.2     Junction with access to Sète harbour

This link was built for commercial traffic (barges of 1000 tonnes) to reach the port of Sète, and is forbidden to recreational craft.

PK 91.7     Bridge (D612, Frontignan bypass)
PK 92.1     Railway bridge
PK 92.2     Frontignan lift bridge, port de plaisance d/s, 30 places on 220m quay, mooring allowed for 3 days, water, electricity, pump-out, showers, crane, slipway, restaurants, town centre r/b

The lift bridge opens each day at 8:30 and 16:00 for a very short period only – don’t be late! During the season a harbourmaster’s assistant is on hand every day from 8:00–11:00 and 15:00–18:00, to assist and orient plaisanciers before and after passage through the raised bridge, for mooring, using the pump-out facility, or for general tourist information. Frontignan, famous for its muscat or mellow yellow wine, is a very pleasant small town on a medieval circular grid pattern.

Canal de Rhone a Sete and river Lez

Looking west towards Sète at the 4-way junction. South (to the left) under a bridge (3.50m air draught) lies a fully-equipped port de plaisance. North (right) is the River Lez, giving access to Lattes (Port Ariane) and Montpellier.

PK 96.1     Bridge (D600)
PK 96.2     Former junction with Canal de la Peyrade, l/b (entrance infilled)
PK 97.3     Railway bridge, narrow passage (9.60m)
PK 97.3     Bridge (D2)
PK 98.0     Outfall in Étang de Thau (see under Étang de Thau conditions of access to Sète port de plaisance, 64 berths, night €28, water, electricity, showers)

For Sète, enter the étang, turn to port and (keeping the safe depth marks to port) head south-west. For the Canal du Midi (i.e crossing the étang) head west-north-west towards the two yellow marks that can be seen. Access to/from Sète is governed by the lifting railway and road bridges, which open for a short time only three times a day. Boats with an air draught of up to 2.30m will pass under the bridges when closed.

Étang de Thau
(Note: distances relate to the straight line across the lake)
PK 0.0    Entrance to lagoon from the Canal du Rhône à Sète
PK 0.3    Navigation crosses dredged shipping channel serving industrial quays on eastern shore
PK 2.3    Roquérols lighthouse, Bouzigues harbour, north side, 10 berths, night €11-28, water, electricity, showers, crane 4t, slipway, pump-out
PK 6.5    Mèze harbour, north shore, 20 berths, night €28.29, water, showers, crane, slipway, pump-out, repairs
PK 16.0    Marseillan harbour, north side, 15 berths, night €38.70, water, electricity, showers, crane 5t, slipway, repairs, restaurants
PK 17.0    Les Onglous lighthouse, entrance to Canal du Midi

Canal de dérivation d’Aigues-Mortes

PK 0.0     Junction with through route (PK 47.3)
PK 0.7     Bridge (D46)
PK 1.9     Main road bridge (D979) and railway bridge
PK 3.6     Junction with through route (PK 53.2)


Canal Maritime

PK 0.0    Junction with Canal du Rhône à Sète at PK 51.0
PK 0.1    Bridge
PK 0.4    Aigues-Mortes port de plaisance 30 berths, night €37, water, electricity, showers
PK 5.2    Bridge
PK 5.3    Confluence with Vidourle
PK 5.5    Le Grau-du-Roi port de plaisance, 30 berths, night €33, water, electricity, showers

River Lez

PK 0.0     Junction with Canal du Rhône à Sète (PK 75.2) access to Paul Riquet boat harbour 300m d/s, 20 visitors’ berths, night €21, water, electricity, showers, slipway
PK 0.4     Channel l/b to Étang de Méjean (small craft only)
PK 1.4     Footbridge (Les Quatre Vents)
PK 2.2     Mas des Salins huts l/b
PK 4.4     Lock (Troisième Écluse)
PK 5.3     Bridge (Méjean), D132
PK 5.5     Lattes marina (Port Ariane) entrance l/b, 6 berths for visitors, night €27-35, Locaboat hire base water, electricity, showers, slipway, pump-out, shops,  restaurants, Montpellier accessible by busLattesPlan