What you get.
Nautical charts
Official hydrographic data plus community corrections — depths, buoys, lights, hazards, harbours, anchorages. Updated daily; a new rock shows up fast.
SonarChart
Crowdsourced bathymetry from sonar-equipped users — much higher-resolution depth than official charts, invaluable in poorly surveyed anchorages.
Community edits
Users report missing buoys, changed depths, new pontoons; verified and integrated quickly. Often more current than official charts for marina layouts.
Route planning
Waypoints and distance calculation — not as clever as Savvy Navvy's auto-routing, but reliable for manual chart plotting with depth checks along the route.
Pros & cons.
- +Best chart coverage globally
- +Community edits keep data current
- +SonarChart high-res depth
- +Offline chart downloads
- +Industry-standard interface
- +Integrates with Garmin plotters
- −No auto-routing — plan manually
- −No tidal overlay on route planning
- −Interface can feel dated
- −Chart regions confusing to buy
- −Annual subscription to keep charts updated
Tips for sailors.
- 01
Download charts before you leave Wi-Fi.
Cell coverage at sea is unreliable — pull your cruising area onto the device on shore.
- 02
Enable the SonarChart overlay.
In settings, turn on the crowdsourced depth shading — far more detail than the standard view, especially in anchorages.
- 03
Report what you find.
Spotted a missing buoy or changed depth? Submit a community edit — your correction might prevent someone's grounding.
- 04
Use alongside Savvy Navvy.
Boating for chart detail + SonarChart depth, Savvy Navvy for auto-routing and passage planning. They complement each other.
Detailed charts for your sailing area.
Plans start from around $15/year, region-based.
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