Scanned charts have to be calibrated; this is so for any moving map scenario where a map is being imported.
Oziexplorer provides functions for doing that. You click on up to 9 points and enter the lat/long for each one.
In some cases, the calibration comes with the (electronically supplied) map. For example the US ONC charts can be purchased in such a ready to use form. Mobile Atlas Creator (v 1.8 or earlier) can similarly generate calibrated (georeferenced) maps from google maps.