Averaging is 1/sec on the Vista HcX, so it only takes about 3 minutes to mark a waypoint. When I first mapped the property and went back to known points I found that they were "off" by the stated accuracy which could have been 10-20 feet on a single reading. When you are averaging you will see the accuracy drop from the initial single reading of say 17 Ft. to 7-10 Ft. depending on tree cover, slope, etc.