Garmin customers can record sonar logs with their GPS chartplotters and upload to Navionics to improve SonarCharts™ . Improved SonarCharts™ can be seen after about one week, on any other compatible plotters, on the WebApp and on mobile devices with Navionics Boating. Sonar log recording is available on the series listed below, others may also work. Check this page for future updates.
Garmin GPSmap Series
Garmin GPSmap Touch Series