I had one briefly and as I recall it was an analog, all metal detector...meaning it will detect every piece of metal in the ground no matter how small. :shocked01: Can go deep but you have to decide what you are going to dig. I would Google the detector and read up on the manual. If you know about where a cache is supposed to be buried, then it may help you find it. If the cache is burried in some other metal than Iron, most good detectors will probably find it , providing it is less than 12 deep. For that particular task, I would find a dealer willing to rent you a unit to try. :yes: Good luck at it and I hope you find them jewels :clapping: