How to Add Official IHM (Spanish Hydrographic Institute) Nautical Charts to SignalK

This tutorial will guide you step by step through integrating Spain’s official nautical charts—provided by the Instituto Hidrográfico de la Marina (IHM)—into your SignalK server using the @signalk/charts plugin.

Note: This method requires an internet connection, as charts are loaded in real time from the IHM server.

Prerequisites

• The @signalk/charts plugin must be installed on your SignalK server.
• Access to the SignalK admin interface (usually at http://your-ip:3000).

Configuration Steps

Follow these steps in the SignalK web interface:

• Go to Server Plugin Config.
• Locate the Signal K Charts plugin and click its configuration button.
• Click the blue + button to add a new chart provider.

Fill in the fields as shown below:

To add the layer:

1. Click the blue + button under the "Layers" section.
2. In the "Layer ID" field, enter: RasterENC.
3. Click Save to apply the configuration.

Finally, restart your SignalK server for the changes to take effect:

• Go to Server > Restart Server and click the restart button.

Viewing in Freeboard-SK

• Open Freeboard-SK in your browser.
• Click the map icon (Charts).
• In the layer list on the left, look for IHM Charts.
• Enable the layer by checking the box.

Done! The IHM nautical charts should now appear overlaid on the map.

Tips

• Image quality: Depends on your internet speed and the IHM server load.
• Zoom range: The service supports zoom levels 1 to 21—do not exceed this range.
• Updates: Charts are automatically refreshed from the IHM server, so you’ll always have the latest official version.

With this setup, you’ll have direct access to Spain’s official navigation charts right in your onboard nautical information system!