Welcome to TNet! I agree with dts52.
Here's a true story that will help.... In 1998, my wife and I were visiting my in-laws in PA. A neighbor walked over and saw my metal detector and told an interesting story. In 1960, his two boys were fighting and one of them threw his brother's silver dollar across the road into tall grass. They couldn't find it and I said if I found it, his son would get it back. The grass was now short and after a few sweeps, my detector indicated a dollar was down 6". So after 38 years, it was down 6".