put the new coil on and swung at the beach got some sparatic hits a low tone then high tone then nothing but it showed 8 to 10 " depth. I dug , nothing I go to all metal still sounds something there . So I dig another 5 or 6 " and a lead fishing weight. The sensitivity or disc does not change anything. I finally got a continous hit and got a pull tab at 5" . This was all dry sand with a landstar.