If your boat's position is incorrect in the Anchor Alert App on the Map page, or it hops around at anchor, the NMEA 0183 sentences from your GPS source may not be supported by the app yet.
NMEA-coded sentences from GPS sources are not standardized. Many different GPS devices are on the market, and support has been added to accommodate them. If you experience this issue, please let us know. We are continuing to add support for all the various NMEA sentences used by different manufacturers.
Please contact our friendly support team via the in-app messenger available in the Anchor App Settings (cog top right of screen) > Other > Support or email at support@PredictWind.com.