Originally Posted by chevvron
we all carry maps when flying don't we?
I'm sure we all do and checking the moving map GPS with the physical map (with all the lines, Wind speed/direction, waypoints, etc drawn on) takes a second or two every few minutes. The configurable GPS warning of approaching controlled airspace is always a welcome reassurance.
My question about the accuracy of your radar is just out of interest. If you have regular arguments with GPS users there must be a problem somewhere as the experience I have of my GPS is that it is extremely accurate and reliable. How far do you consider the these guys were inside your airspace?