Using this Garmin yardage device/watch, I tested the accuracy of the granite stone yardages on the tees today. Most were comparable but a few, like #18, were off. The tee in the ground with the white tape is where the stone would be located according to this device. However, before I move any, I want to confirm how this measures up to other devices. I will say my Bushnell range finder was always within a yard of the Garmin. I would say this technology is pretty accurate these days.