Community Edits are not yet viewable on Humminbird. They've not added the "switch" to the menu system yet.
SonarCharts are viewable on both manufacturers. You need to refer to the Compatibility Guide (Compatibility at the lower right of most every page of the Navionics website) to see which plotters have the necessary "switch")
at this time, Humminbird users can also contribute to SonarCharts. Navico is view-only.