Could someone give me a good estimate on the Cibola's depth capability in mild to moderate soil with the stock coil. Targets would be colonial coins and Civil War relics ranging in size from cuff buttons to belt plates. Lets say the iron trash content is low. I have read many rather conflicting accounts of this detectors performance. One user states that 7 inches was about the max for coins while a well known relic hunter claimed to have found flat buttons at 21 inches. I realize there are lots of variables that affect depth in different soils and situations, but I would would like to know what I might expect out in the woods relic hunting away from electromagnetic interference.