Nautical Routing & Tidal Streams Data

Pre-compiled nautical routing graphs for the SignalK RouteIQ nautical route planner and tidal/current data sources for the SignalK Tidal Currents plugin.

Two kinds of tidal/current data, worth knowing apart before picking a source:

• Predicted currents (astronomical, no weather) — static harmonic tide tables, computed from the sun and moon alone. Small files, never need refreshing, but blind to wind, storm surge, and river flow.
• Forecast currents (tide + weather) — gridded ocean-model output that combines tides with wind, weather, and (where relevant) river discharge. Refreshed regularly — daily for most sources, up to 4x/day for a few — from real forecast models.

Both kinds appear on the coverage map below, in the color legend and, per-region, in the interactive coverage map.

Licensing: Code and tooling are GPLv3. Original/compiled data catalogs and databases are CC-BY-NC-4.0. Third-party data sources (NOAA, BSH, FES2014, OpenCPN) follow their own upstream terms — see the License & Attribution section below.

Routing databases are published as .sqlite.gz (gzip-compressed) assets on the rolling routing-databases-latest release — the same way the forecast-current GRIB2 files are published — so rebuilding a region never grows this repository. The repo itself holds only the small regions/**/*.index.json descriptors that routing-index.json is generated from. The plugin's download dialog resolves the release URL and handles decompression automatically.

Coverage

Tidal Streams & Currents

For an interactive version — pan, zoom, and click any region to see its name, provider, and description — open tide-current-coverage.geojson; GitHub renders .geojson files as a live map automatically.

Routing Databases

Data Sources

Tidal/current data comes from three kinds of upstream sources, each suited to a different need:

type	Source	What it provides
harmonic	OpenCPN / XTide	ASCII harmonic constituents for named stations — small, static files, no refresh needed
grib2	BSH	Regional gridded current forecasts (tide + weather + river forcing) for the North Sea, Baltic and Elbe, refreshed per model cycle
grib2	NOAA NOS OFS	Regional gridded current forecasts for US waters (tide + weather + river forcing) from the NOS Operational Forecast Systems (currently Chesapeake Bay, San Francisco Bay, Salish Sea & Columbia River, northern Gulf of Mexico, West Coast, Gulf of Maine, Delaware Bay, Tampa Bay, Cook Inlet, Lakes Erie/Michigan-Huron/Ontario/Superior, New York Harbor, and the St. Johns River), extracted from model output and re-encoded as compact GRIB2 by scripts/tide-current, refreshed daily via the rolling ofs-currents-latest release
grib2	Copernicus Marine (CMEMS IBI)	Regional gridded current forecasts (tide + weather + river forcing) for the Bay of Biscay, NW Iberia/Galicia, Portugal, and the Gulf of Cadiz/Gibraltar Strait, extracted from the Copernicus Marine IBI analysis-and-forecast model and re-encoded as compact GRIB2 by scripts/tide-current, refreshed daily via the rolling ibi-currents-latest release
grib2	Copernicus Marine (CMEMS NWS)	Regional gridded current forecasts (tide + weather + river forcing) for the UK, Ireland and English Channel, extracted from the Copernicus Marine NWS (North West European Shelf) analysis-and-forecast model and re-encoded as compact GRIB2 by scripts/tide-current, refreshed daily via the rolling nws-currents-latest release
grib2	Copernicus Marine (CMEMS MED)	Regional gridded current forecasts (tide + weather forcing) for the Mediterranean Sea, extracted from the Copernicus Marine MED analysis-and-forecast model and re-encoded as compact GRIB2 by scripts/tide-current, refreshed daily via the rolling med-currents-latest release
utcef	FES2014 (via AVISO+)	Dense-grid harmonic tidal current predictions derived from the FES2014 global tide model — static, no refresh needed
utcef	NOAA CO-OPS	Official harmonic constituents of ~850 NOAA current-prediction reference stations (US East/West Coast, Gulf of Mexico, Alaska, Hawaii, Puerto Rico), converted by scripts/NOAA — static, astronomical predictions valid for years

See specs/tide-current-catalog.md for the full catalog schema and specs/utcef-specification.md for the UTCEF file format.

Machine-Readable Catalogs

Catalog	File	Spec
Routing graph databases	routing-index.json	specs/routing-database-catalog.md
Tide/current data sources	tide-current-index.json	specs/tide-current-catalog.md
Unified Tidal and Current Exchange Format (UTCEF)	—	specs/utcef-specification.md

Quick Start

RouteIQ (Routing)

1. Install the SignalK RouteIQ nautical route planner
2. Set routingDataDir in the plugin config to a directory on your server
3. Download the .sqlite.gz file(s) for your region(s) from the routing-databases-latest release or use the plugin's built-in "Manage Routing Data" dialog
4. The plugin automatically decompresses .sqlite.gz files on download — just use the dialog
5. Restart the plugin

Multiple .sqlite files can coexist in the same directory — the plugin merges them at startup.

Tidal Currents

1. Install the SignalK Tidal Currents plugin
2. The plugin reads tide-current-index.json to list available data sources
3. Download the sources for your region via the plugin UI

Contributing

We welcome new regions and data sources! See:

• CONTRIBUTING.md for routing database format and submission
• specs/tide-current-catalog.md for adding new tide/current data sources

License & Attribution

Routing databases

Each database file may have its own licensing terms as documented in its metadata.url and metadata.contributor fields (see routing-index.json). Check individual file metadata for attribution and license information.

Tidal/current data

• NOAA CO-OPS current stations (utcef sources under regions/*/noaa_*.utcef): derived from the official NOAA Tides & Currents harmonic constituents — public domain, U.S. Government work (17 U.S.C. §105). Predictions are astronomical only; actual currents deviate with weather and river flow. Not an official NOAA product.

• NOAA NOS OFS surface currents (grib2 files on the ofs-currents-latest release): surface u/v extracted and re-encoded from official NOAA NOS Operational Forecast System model guidance — public domain, U.S. Government work (17 U.S.C. §105). These files are subsampled, repackaged model guidance produced by this repository — not an official NOAA product and not endorsed by NOAA; do not use for primary navigation.

• Copernicus Marine (CMEMS IBI) surface currents (grib2 files on the ibi-currents-latest release): surface u/v extracted and re-encoded from the Copernicus Marine Service IBI analysis-and-forecast model, redistributed under the Copernicus Marine license. Per the license's terms for a modified/reformatted product: "Generated using E.U. Copernicus Marine Service Information (https://doi.org/10.48670/moi-00027)". These files are geographically subsetted and reformatted from netCDF to GRIB2 by this repository — not an official Copernicus product and not endorsed by Mercator Ocean International; do not use for primary navigation.

• Copernicus Marine (CMEMS NWS) surface currents (grib2 files on the nws-currents-latest release): surface u/v extracted and re-encoded from the Copernicus Marine Service NWS (North West European Shelf) analysis-and-forecast model, produced by the UK Met Office (NWS-MFC) and redistributed under the same Copernicus Marine license. Per the license's terms for a modified/reformatted product: "Generated using E.U. Copernicus Marine Service Information (https://doi.org/10.48670/moi-00054)". These files are geographically subsetted and reformatted from netCDF to GRIB2 by this repository — not an official Copernicus product and not endorsed by the Met Office or Mercator Ocean International; do not use for primary navigation.

• Copernicus Marine (CMEMS MED) surface currents (grib2 files on the med-currents-latest release): surface u/v extracted and re-encoded from the Copernicus Marine Service MED (Mediterranean Sea Physics) analysis-and-forecast model, produced by CMCC (Italy) and redistributed under the same Copernicus Marine license. Per the license's terms for a modified/reformatted product: "Generated using E.U. Copernicus Marine Service Information (https://doi.org/10.48670/mds-00359)". These files are geographically subsetted and reformatted from netCDF to GRIB2 by this repository — not an official Copernicus product and not endorsed by CMCC or Mercator Ocean International; do not use for primary navigation.

• OpenCPN / XTide harmonics (harmonic sources): see the OpenCPN project for licensing of the underlying station data.

• UTCEF / FES2014-derived datasets (utcef sources, e.g. files under regions/europe): derived from the FES2014 global tide model, produced by Noveltis, LEGOS and CLS and distributed by AVISO+, with support from CNES. Redistribution follows the AVISO+ License Agreement (scientific and non-commercial use).

  These derived datasets are not endorsed by, affiliated with, or supported by AVISO, CNES, or any FES2014 copyright holder. If you use this data, please cite: "FES2014 was produced by Noveltis, Legos and CLS and distributed by Aviso+, with support from Cnes (https://www.aviso.altimetry.fr/)". To access the raw global FES2014 dataset directly, visit AVISO+.

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Maintained by the SignalK RouteIQ and Tidal Currents community.