My apologies for not being clear. A G Chart is from Garmin and is a navigational chart to be inserted into one of their GPS's. They are discontinued and have been for many years. I have the choice of going back to my old Garmin GPSMAP 215 that uses G Charts. They, I believe were replaced with BLUECHARTS in later models. The built in world chart will suffice for what I need but not nearly with the detail as with a chart card. I have a northern Lake Huron I would be able to exchange for the Lake Michigan chart or I will just pay someone for it.
Thank you, I hope I cleared that up
