Select your product to confirm this information applies to you
Garmin Supplemental/Additional Chart Coverage
Many Garmin chartplotters come with built-in charts, like BlueCharts for coastal coverage, or LakeVu for inland lake coverage. Garmin also offers supplemental (additional) charts which can provide a chartplotter with an area of water it doesn't cover with it's built-in chart, or provide additional features.
Supplemental mapping provides additional chart features and will display priority over the built-in map on the individual or networked chartplotters where area coverage overlap occurs. If the built-in chart is preferred, remove the supplemental chart card. Chartplotters with built-in Garmin Navionics+ mapping cannot utilize BlueChart g3 supplemental maps.