I emailed humminbird and called their customer service about the "Donut" issue. Their response is the "donut" will be there if you are below 1 mile an hour. I asked if you drifted a half mile away at less than .5 miles an hour would the gps show your previous location with the donut or the new location with the donut. Their response was that it would show the new location with the donut. Is this True?