Plage de la Pointe de Grignon

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 6.9 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 01:48 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.