dataset · United Kingdom

Defra's Marine Digital Elevation Model (DEM) - 6 arc seconds

This dataset contains Digital Elevation Model (DEM) shapefiles for the waters surrounding the United Kingdom to a depth of 200 metres. This resolution is 6 arc seconds which covers the widest possible geographic area. Geographic coordinates were used throughout and the DEM is referenced to the ETRS89 datum horizontally and Chart Datum vertically. All input data was made available under licence by the UK Hydrographic Office (UKHO) to Defra for the purpose of DEM creation. Attribution statement: ©

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Source details

Licence: ["There are no public access constraints to this data. Use of this data is subject to the licence identified.", "There are no public access constraints to this data. Use of this data is subject to the

Evidence quality: 50.5

Listed in data.gov.uk public catalogue API on 2026-10-16; relevance/value screened (haiku).

Metadata checked: 2026-10-14T13:20:00.000Z

What's in it

Data offered docs-verified: marine DEM (seabed elevation) for UK surrounding waters to 200 m depth
Coverage docs-verified: Waters surrounding the United Kingdom; latitude 50° to 60.9°, longitude -11.1° to 1.8° · No temporal coverage stated; metadata reference dates only: created 2017-03-31, revised 2018-01-23
Resolution docs-verified: 6 arc seconds (geographic coordinates)
Update frequency docs-verified: As needed (no fixed schedule)
Formats docs-verified: SHP (zipped) · GPKG (zipped) · GeoJSON (zipped) · File Geodatabase GDB (zipped)
Access docs-verified: Open download; no public access constraints; Open Government Licence (OGL). No authentication listed.

Useful for

Use cases llm-inferred: Offshore bathymetry input for coastal and estuarine flood risk model boundaries · Seabed level context for marine outfall or cable route feasibility · Sea-depth banding and coastal GIS mapping for planning-stage site context
Audience llm-inferred: flood risk consultants · coastal engineers · marine consultants · GIS analysts · hydrographers

Limitations

Constraints llm-inferred: Marine only: covers UK surrounding waters to 200 m depth, not land · Vertical reference is Chart Datum, not Ordnance Datum; convert before joining with land DEMs · Metadata lists EPSG:27700 but the summary says geographic coordinates on ETRS89; confirm CRS on download · Source reference dates are 2017 to 2018; check currency against recent UKHO survey data · Input bathymetry was licensed from UKHO; check for any additional terms beyond the OGL · A WMS link is listed without format or service details

Evidence

Check upstream coverage, uncertainty and licence before use. Station observations are not forecasts or design levels.