Fetching this spot's conditions…
Tip of the moment
Fetching this spot's conditions…
Tip of the moment
La Tranche-sur-Mer · Pays de la Loire
Today's take
Best window: 17:00–20:00. Excellent conditions.
Water temperature
19.3 °C
Verdict
Glassy
Underwater visibility
~5.4 m
satellite reading from yesterday
When to go
Good from 17:00 to 20:00.
Pin colours:swimmablecautionnot advisedconditions not loaded yet
Forecasts come from ~8 km resolution models: very local effects (a sheltering pier, a lagoon pass) are not captured.
Sea-state data comes from a marine model cell about 8.5 km from this point — local nearshore conditions can differ.
Wave heights are significant heights: individual waves up to 2× this height still occur.
Four wave models are compared for this point: EWAM, GWAM, Météo-France WAM and ECMWF WAM.
Tide times derived from modelled sea level (± a few tens of minutes) — not official tide tables.
Missing data is shown as missing — never silently estimated.
Beach locations from OpenStreetMap — © OpenStreetMap contributors (ODbL).
Weather and marine data: Open-Meteo.com (CC BY 4.0), wave models from the Deutscher Wetterdienst (CC BY 4.0). Forecasts are not guarantees. · Data fetched at 14:09 UTC
Water clarity generated using E.U. Copernicus Marine Service Information.
Windows, comfort score and verdicts are computed by oswim from this data — modified values, not the institutes' raw figures.
min 8 · max 22 km/h · north-east sector · gusts 42 km/h
Visibility · 46 – 54 km
Good visibility.
Loss of bearings and collision risk
Post-rain pollution · 0 mm over 24 h
When it rains hard, runoff from roads and fields and sewer overflows carry bacteria out to sea. Nothing significant has fallen in the last 24 hours.
Official sampling is weekly at best; between two samples, recent rain is the recognized warning signal (EEA)
Jellyfish: no recent info. If you're there, tell us what you see — even “none” helps the next swimmer.
Water quality · Excellent · 2025 season
Computed from the samples of the last four bathing seasons. It says what the water here has been, not what it is today: after heavy rain, even an excellent beach degrades for a day or two.
Health authority classification (EU directive 2006/7/EC), published once per bathing season
In all cases: bright swim cap and tow float so boats can see you.
Consolidated ladder: World Aquatics / World Triathlon / FFTri rules + manufacturer thermal guides