Crowd Depth

Help improve nautical charts by sharing depth data from your vessel.

Most of the world's coastal waters have never been surveyed, or were last surveyed decades ago. Every time you cruise, your depth sounder measures water depths that could fill those gaps. Crowd Depth collects those soundings — depth, position, and time — and contributes them to crowdsourced bathymetry programs, where they help identify uncharted hazards, update charts with recent depth changes, and make navigation safer for everyone.

How it works

1. Collect — The plugin runs quietly in your Signal K server, recording depth soundings with GPS coordinates and timestamps as you navigate. If you already log data with a History API plugin (like signalk-to-influxdb2), it reads from that instead of storing anything extra.
2. Correct — Soundings are adjusted for your configured transducer and antenna offsets, so the reported depth and position reflect the water, not your installation.
3. Contribute — Once a day, the plugin uploads your soundings to Open Waters, an IHO trusted node — an organization authorized to submit crowdsourced bathymetry to the IHO Data Centre for Digital Bathymetry, hosted by NOAA, on behalf of mariners. From there your soundings become part of the public record, available to hydrographic offices, chart makers, and navigation apps under a CC0 public domain dedication.

You stay in control: sharing can be anonymous (a random UUID instead of your vessel name and MMSI), and you can disable the plugin at any time.

Installation

• Install the crowd-depth plugin from the Signal K server AppStore.
• Enable the plugin and open its settings.

Configuration

Accurate offsets are what turn raw sounder readings into chart-quality data — take a few minutes to measure them. Where your vessel already reports sensors.* and design.* paths, the plugin pre-fills the defaults.

Depth

• Path — Which depth path to report (belowSurface, belowTransducer, or belowKeel), depending on what your instruments provide. Defaults to the first one with data.

Depth Sounder

• Depth source — The sensor to record when more than one reports depth, so soundings stay pinned to a single transducer.
• Offsets (required) — Transducer distance from the bow, from the centerline (positive to starboard), and below the waterline, in meters.
• Details (optional) — Draft, make, model, frequency, and transducer type. Included in report metadata to help downstream processors assess data quality.

GPS Receiver

• Position source — The receiver to record when more than one reports position, so all soundings share one antenna location.
• Offsets (required) — Antenna distance from the bow, from the centerline (positive to starboard), and above the waterline, in meters.
• Details (optional) — Make and model.

Data Sharing

• Share data anonymously — Withhold your vessel name and MMSI and report under a randomly generated UUID instead.

By enabling the plugin, you agree to share your position and depth data with the IHO data collection service under CC0.

For developers

• Data is reported daily at midnight local time; set a cron-style schedule in the BATHY_DEFAULT_SCHEDULE environment variable to change it.
• Reports go to BATHY_URL (production: https://depth.openwaters.io, otherwise http://localhost:3001).
• A helper CLI xyz-to-geojson (installed with the package) converts XYZ files to GeoJSON.

See CONTRIBUTING.md for repo layout, the local Signal K npm link workflow, testing, and releases.