I was asked to do a test on a vicky penny at 19" and i buried it at 20" tuned up the blisstool and got nothing not a wisper , and that was with the 11 DD coil now i think the 15" coil would have nailed that , so i buried it at 16" in dry badd ground keep in mind the gold bug ground phaze reads 86 and thear is black sand in this ground and its dry but the blisstool pounded this target and I am operating in discriminate to knock out Iron and small foil its still nailing it if you want those deep mini balls and coins this is no gimmick dont wait to place your order , I jumped on this one and have not been disapointed another machine that will get you this depth is the GPX 4800 or 5000 [video]http://www.youtube.com/watch?v=Y4VTYSGxPf0&feature=plcp[/video]