Anyone who uses
Google earth to create
charts or use as a
navigation program should be aware of the Terrain problem:
If you have Terrain turned on
Google earth's positions will be very different from your
GPS position. The testing I did showed it be off by as much as 600 feet.
This problem is more apparent in the newest version of
Google earth (V5.2) because it turns on Terrain by default. In the new version, Terrain is an option in the 3D View (Show Terrain - checkbox). In versions prior to 5.2, Terrain was a layer that you turned on or off.
When Terrain is off, I have found
Google earth to be VERY accurate.