The Gold Bug has most of the options you'll need in a prospecting detector with none of the extra bells and whistles which make up most prime-of-the-line versions. The MINELAB Gold Monster a thousand at 45kHz represents the gold standard for sensitivity, whilst detectors all around seven-18kHz give a stability https://archives.profsurv.com/forum/Professional-Surveyor-Magazine-Discussion/Education/-151484.aspx