Navionics, the leader in location-based content for the recreational boating and outdoor markets, announced today the release of a new SonarCharts chart card for use with several Garmin GPS chartplotters. Featuring extraordinary bottom contour detail of up to 1 foot in the US and Canada, the new version of SonarCharts HD bathymetry map for use with several Garmin GPS chartplotters offers the most detail available anywhere, and is great for increasing awareness of shallow waters and locating fishing areas at any depth level. The SonarCharts card also includes navigational aids, providing a complete resource for all boating activities.