Signal K Charts Provider Simple

A lightweight Signal K server plugin for managing local nautical charts, written in strict TypeScript. Supports MBTiles, S-57 ENC, BSB raster, and world basemaps with automatic conversion via Podman containers.

Features

• Local Chart Management: MBTiles (raster and vector), with folder organization and enable/disable toggles
• Download Manager: Built-in download queue with progress tracking and ZIP extraction
• Chart Catalog: Browse and download charts from chartcatalogs.github.io with automatic update notifications
• S-57 ENC Conversion: Convert IENC/ENC charts to vector MBTiles with full S-52 symbology in Freeboard-SK
• BSB Raster Conversion: Convert BSB/KAP raster charts and Pilot Charts to raster MBTiles
• World Basemaps: GSHHG and OSM coastline basemaps for offline use
• Custom Upload: Upload your own ZIP files containing S-57 ENC or BSB charts for conversion
• Modern Web UI: Material Design 3 interface with drag-and-drop
• Dual API Support: Compatible with Signal K v1 and v2 API

Installation

From Signal K Appstore

1. Open your Signal K server admin interface
2. Navigate to Appstore
3. Search for "Charts Provider Simple"
4. Click Install

Manual Installation

cd ~/.signalk
npm install signalk-charts-provider-simple

Configuration

1. Navigate to Server → Plugin Config → Charts Provider Simple
2. Set your chart directory path (defaults to ~/.signalk/charts-simple)
3. Enable the plugin
4. Restart Signal K server

Usage

Web Interface

Access the plugin's web interface through your Signal K server:

http://[your-server]:3000/plugins/signalk-charts-provider-simple/

The interface provides four tabs:

1. Manage Charts:

   • View all charts with metadata (name, bounds, zoom levels, size)
   • Enable/disable, organize into folders, upload, delete, rename
   • S-57 charts shown with ENC badge
   • Converting charts shown with progress indicator

2. Download from URL:

   • Download charts directly from any URL
   • Supports .mbtiles and .zip archives
   • Download queue with progress tracking

3. Convert:

   • Upload ZIP files containing S-57 ENC (.000) or BSB raster (.kap) charts
   • Drag-and-drop or click to select files
   • Configurable zoom levels for S-57 conversion
   • Live conversion progress with log viewer

4. Chart Catalog:

   • Dynamic catalog from chartcatalogs.github.io
   • One-click download for MBTiles charts (NOAA)
   • Download & convert for S-57 ENC, BSB raster, Pilot Charts, and basemaps
   • Automatic update notifications (Signal K delta + tab badge)
   • Category filtering (MBTiles / RNC / IENC / General)

Supported Formats

Format	Source	Conversion	Output
MBTiles	Direct download	None needed	Raster or vector tiles
S-57 ENC (.000)	IENC catalogs, custom upload	GDAL + tippecanoe (Podman)	Vector MBTiles with S-52 styling
BSB Raster (.kap)	RNC catalogs, custom upload	GDAL (Podman)	Raster MBTiles (PNG)
Pilot Charts (.kap in .tar.xz)	Pilot catalog	GDAL (Podman)	Raster MBTiles (PNG)
GSHHG Basemap	General catalog	GDAL (Podman)	Raster MBTiles (PNG)
OSM Basemap	General catalog	GDAL (Podman)	Raster MBTiles (PNG)

Compatible Chart Plotters

• Freeboard SK — full S-52 symbology for S-57 vector charts
• OpenCPN

Requirements

• Node.js >= 22.5 — uses the built-in node:sqlite module, no native compilation needed
• Not supported on Cerbo GX — Venus OS ships Node.js 20, which lacks the node:sqlite module. Use v1.6.x if you need Cerbo support.

Optional: Podman (for chart conversion)

To convert S-57 ENC, BSB raster, Pilot Charts, or basemaps, Podman must be installed. The plugin uses standard container images that are pulled automatically on first use:

• ghcr.io/osgeo/gdal:alpine-small-latest — GDAL for format conversion
• ghcr.io/dirkwa/signalk-charts-provider-simple/tippecanoe — tippecanoe for vector tile generation (multi-arch: amd64 + arm64)

# Debian / Ubuntu / Raspberry Pi OS
sudo apt install podman

# Fedora / RHEL
sudo dnf install podman

MBTiles charts work without Podman. Chart conversion is limited to 2 concurrent jobs.

Legal Notice

Chart Metadata Editing

This plugin includes a feature to edit chart metadata (chart names) in MBTiles files. This feature is intended for personal use only.

Important:

• The Signal K community is not responsible for any illegal use of this feature
• Modified charts are automatically marked with "USER MODIFIED - DO NOT DISTRIBUTE - PERSONAL USE ONLY" in the description field
• Do not distribute modified charts - this may violate copyright laws
• Use this feature responsibly and only for organizing your personal chart library

Acknowledgments

Inspired by Signal K Charts Plugin by Mikko Vesikkala.

Contributing

Contributions are welcome! Please feel free to submit a Pull Request.

Support

For issues and feature requests:

• GitHub Issues: https://github.com/dirkwa/signalk-charts-provider-simple/issues