I once read that you should always re-scan after you've pulled your find from the ground. I was in a grassy park recently and had a good, strong hit. I dug about 2" and pulled out a quarter. After re-scanning, I pulled out 2 more quarters in the same plug, adjacent to the first. Re-scanned and pulled out another quarter. Final re-scan found me a Susan B. dollar. This park is used for folk music concerts and town events. As it goes, someone sat down and it all fell out. Great advice!