Data sources & map attribution

Basemap, measurements, forecasts, and third-party licences

The sea-level map combines open map tiles with public authority measurements and forecasts. This page lists providers and how they are used on this site.

Important notice

This sea-level map is an unofficial visualization for general information only. It is not affiliated with, endorsed by, or operated on behalf of any data provider listed below.

Values may be delayed, converted (e.g. cm, datum offsets), interpolated, or incomplete. Forecasts are model output, not measurements. Do not use this site for navigation, flood warning, port operations, or any safety-critical decision.

No warranty is given as to accuracy, completeness, or timeliness. Use at your own risk.

The map application, layout, and explanatory text on this website are © the site operator unless stated otherwise. Third-party data remains subject to the respective providers’ terms and licences.

Map background (tiles)

BasemapCARTO (Dark Matter / Positron styles)
Geographic dataOpenStreetMap contributors
RenderingMapLibre GL, deck.gl
On-map credit© CARTO, © OpenStreetMap contributors

Water level & wind data

ProviderRegionUse on this siteLicence / note
Pegelonline (WSV)GermanyMeasured water levels (Pegelonline API / MQTT)Federal Waterways and Shipping Administration (WSV) — unvalidated raw data; Data Licence Germany – Zero – Version 2.0; no official status.
BSHGermanyTide forecasts and coastal station metadataFederal Maritime and Hydrographic Agency. Data adapted/processed (future integration includes conversion to MSL for international comparison). Usage is royalty-free under the Data Licence Germany – Attribution – Version 2.0; not for navigation.
RijkswaterstaatNetherlandsMeasured water levels (Waterinfo / RWS)Dutch Ministry of Infrastructure and Water Management — attribution required.
SHOM / REFMARFranceTide gauge observations (pilot stations)SHOM / REFMAR — Open Licence (Etalab v2.0); cite source as requested by REFMAR.
MVBBelgiumCoastal tide measurements (Meetnet Vlaamse Banken)Flemish Hydrography — open data; attribution required.
Environment Agency (UK)United KingdomTide gauge readings (Flood Monitoring API)Open Government Licence (OGL) where applicable.
DMIDenmarkTide gauge observations (oceanObs API, sealev_ln)Danish Meteorological Institute — open data; attribution required.
MET NorwayNorwayTidalwater measurements and forecasts (10-minute resolution)MET Norway — see Terms of Service; User-Agent identification required.
DWDGermanyWind observations (10-minute station data)Deutscher Wetterdienst — dl-de/by-2-0 open data licence.

Reference values

Mean high water (MThw) reference values for German stations are derived from pegel yearbook statistics (e.g. BSH Pegel data). They are shown for comparison only and are not live measurements.

Website content

Text, layout, graphics, and the map user interface on this website are © the site operator unless otherwise stated. Fonts: Barlow (SIL Open Font License).