Browsing enough of these forums for long enough you see so many claims of coins being found at unbelievable and even unreasonable depths with detectors not known for depth. A certain percentage of those can be attributed to embellishment or error , but a certain percentage..... especially from experienced detectorists not known for fish stories.... are true. Another reason why certain isolated " tests " do not necessarily always match what you might experience hunting various places out in the field.
I am going to make you roll your eyes here , but I have certain areas where the soil make up and other variables make it virtually impossible to detect and identify a long buried quarter past 6 or 7 inches.....while at a particular spot that remains wet much of the year I have detected and identified 3 separate long buried quarters laying on top of a clay layer 12 inches below the surface of the topsoil ......and with a 5x8 Garrett coil !! and that exceeds air test results
" Impossible " you might say , well I would agree with you if it had not happened. They were all coated with a green/black , wet " halo " from being wet much of the time and interaction with soil minerals. Say what you want , but that illustrates a pattern between soil , target , and detector , that has to be happening all the time....just usually so subtle you don't notice it. As soil composition , moisture , and various other variables change , so does the detection field to some extent. There are places it can even change drastically in just a few feet , and we are blissfully unaware of it.
Doubt if you want , I wont be upset. I'm 47 and have been detecting since I was 18 , yet I am often surprised by things I didn't think possible before.