Map › France › La Torche (Bretagne) › Lagune du Letty / Mer Blanche
Bretagne · Benodet - Fouesnant · Benodet
Lagune du Letty / Mer Blanche
also known as Le Letty, La Mer Blanche, Pointe de Groasguen, Cor de Groasguen, Pointe Saint-Gilles
Nearby La Torche (Pointe de la Torche, Penmarc'h) 20 km · straight-line distance
When it fills in
No thermal cycle to wait for. The wind is synoptic and can be in at any hour; what opens and closes the session is the tide, because the lagoon only holds water around high water and the ocean side only opens once it has drained.
The wind
Direction
Character
synoptic
fills in: No thermal cycle to wait for. The wind is synoptic and can be in at any hour; what opens and closes the session is the tide, because the lagoon only holds water around high water and the ocean side only opens once it has drained.
Typical strength
No measurement exists at the lagoon. The long-run average at the nearest inland airport station is 9 kt with gusts near 23 kt and a westerly bias, which is regional background rather than a session figure. This is a synoptic spot, and the tide window decides the day more than the wind number does.
Direction to shore
South through south-west is the working band, with east usable on the lagoon side. On the filled lagoon those directions arrive over the Mousterlin dune cordon and land side-onshore on flat water; on the ocean beach south-west is side-onshore.
Dominant direction
Most directions can be used on one side or the other: south and east for the lagoon, southwest for the ocean side.
Forecast
Month by month
- Jan48
- Feb56
- Mar69
- Apr, riders' month46
- May, riders' month47
- Jun, riders' month34
- Jul, riders' month34
- Aug, riders' month35
- Sep, riders' month43
- Oct55
- Nov62
- Dec62
per cent of the month at force 4 or more
Ringed months are the ones riders and schools name: Apr, May, Jun, Jul, Aug, Sep.
- 12Jan11°
- 12Feb10°
- 14Mar11°
- 12Apr13°
- 11May16°
- 11Jun19°
- 11Jul18°
- 10Aug19°
- 11Sep18°
- 12Oct16°
- 14Nov14°
- 13Dec12°
avg knots per month · water °C below · season highlighted
| Month | Force 4+ | Knots | From | Air | Water |
|---|---|---|---|---|---|
| Jan | 48% | 12.3 kt | WNW | 7.5°C | 10.6°C |
| Feb | 56% | 12.2 kt | W | 9°C | 10.3°C |
| Mar | 69% | 13.8 kt | SW | 9.9°C | 11°C |
| Apr | 46% | 11.9 kt | WNW | 11.2°C | 12.7°C |
| May | 47% | 10.8 kt | NNE | 14.5°C | 16°C |
| Jun | 34% | 10.5 kt | W | 17.5°C | 18.5°C |
| Jul | 34% | 10.7 kt | WSW | 18.4°C | 17.8°C |
| Aug | 35% | 10.3 kt | NW | 19°C | 18.8°C |
| Sep | 43% | 11 kt | W | 16.9°C | 18.4°C |
| Oct | 55% | 12.2 kt | SSW | 14.9°C | 16.4°C |
| Nov | 62% | 14.1 kt | WSW | 11.8°C | 14°C |
| Dec | 62% | 13.3 kt | WSW | 8.9°C | 11.6°C |
modelled
A weather model's cell over this place, not a station on it. Good for comparing places, weaker for one beach.
Modelled from weather reanalysis on a 10–25 km grid (2022-2024), not a ground station: reliable for trade and synoptic winds, understates thermal sea breezes and valley winds. The typical daily max and the direction are columns of the table above, month by month. Highlighted months are the riding season from the spot record.
ERA5 reanalysis grid point (modelled) · Open-Meteo historical weather API — ECMWF ERA5/ERA5-Land reanalysis, not a ground station · 2022-2024
The water
Type
tidal lagoon and adjacent ocean beach
Standing depth
Shallow over large parts of the filled lagoon, on fine sand, and standable across much of it near high water. The eastern end is shallower and rocky underfoot, shallow enough that a foil grounds out. No measured depth is published and the banks shift, so read the water rather than a number.
Tides
Two spots on one tide clock. The lagoon fills around high water and that is the flat-water session; on the ebb it drains out near Groasguen and empties, and only then can you walk across the sand to the ocean beach. Check the tide table before the wind forecast.
Temperature
17°C summer · 10.7°C winter
Wetsuit
Cold Atlantic water; a full wetsuit is normally needed, with thickness depending on season.
Currents
Strong on the ebb where the lagoon empties towards the sea near Groasguen, and it builds as the level drops. The flood and the top of the tide are the window. The outflow runs seaward, so a swim caught in it takes you away from the lagoon.
Your level
The scene
What riders come here for
Launch and rules
three ways on to the water, and what each one asks of you
With a school or a boat
4 schools name this spot
On your own
Room to launch: Tidal and variable; the lagoon empties at low tide and access/rigging choices change with water level.
Somewhere else
La Torche (Pointe de la Torche, Penmarc'h), 20 km
Every spot within 40 km is on the map at the top of this page, with its distance under it.
Rescue
VHF channel 16
Launch
Lagoon access is the slipway below UCPA at Le Letty. At low tide park by UCPA or at the Pointe / Cor de Groasguen; at high tide the Kerler beach car park serves the ocean side, a long walk that passes a naturist beach. Inside, the filled lagoon is flat fine sand with the water lying thin over it.
Space
Tidal and variable; the lagoon empties at low tide and access/rigging choices change with water level.
Rules & access
Access rules drift faster than anything else we hold — check locally, and propose an edit if this has changed.
Rider tips
- Check the tide height and the coefficient before you drive; the lagoon only works filled, and the ocean side only when it is empty.
- Ride the flood or the full lagoon and get off before the ebb; the current where the water exits near Groasguen is strong.
- Launch from the slipway below UCPA at Le Letty. At low tide park near UCPA or at Pointe de Groasguen; at high tide the Kerler beach car park serves the ocean side, with a long walk.
- Ask a local rider or one of the schools how the crossing to the ocean side is set up right now before you walk over; the sand and the access change.
- Stay off the fenced dunes and out of the signed nesting zones around Kerler and the spit, and keep the dog on a lead in the breeding season.
- Keep foils out of the east of the lagoon; it is shallow and rocky.
- Put the sea emergency number in your phone before you go: 196, or channel 16 on VHF.
Getting there
Airport
Quimper Cornouaille is the nearest airport; Brest and Lorient are the regional alternatives.
Route
By public transport: train to Quimper, then BreizhGo bus line 941 to Benodet. Fouesnant to Benodet is 8 km, about 12 min by road.
Staying
Benodet and the Letty area have tourist accommodation, including UCPA and nearby campings; no kite-stay pricing is published.
No-wind days
sailing · stand-up paddle · kayak · coastal walks · birdwatching around the Mer Blanche
Photos
FAQ
Is it suitable for beginners?
No, the required level is intermediate because of strong ebb current, rocks and the need to time sessions precisely with the tide.
What is the wind like?
South and east winds work best for the lagoon side, while southwest suits the ocean side; direction must be matched to the tide and side of the spot.
Are there rules?
As of 2026, visitors must stay on paths, avoid signed nesting zones, not bathe in the lagoon and not cross the protective enclosures near the Mer Blanche spit.
What are the main hazards?
The lagoon drains quickly on the ebb, producing strong current, and rocks and shallow patches are found in the eastern lagoon.
Last updated: August 2026