Good Portable GPS
WAAS GPS is accurate to 10 meters and it has proved to be so for me all of last season. This is vastly improved over GPS from the mid nineties. Digital charts are made from paper charts and are every bit as accurate. The thing that causes the problem is that most paper charts have inaccuracies and most have not been updated in many years. Some in over 50 years. These charts were made when the technology used to make charts today was not in existence. The bottom line is that Lat and Lon from a WAAS GPS is more accurate in many cases than the chart on which it is plotted.