Well I tried to give you a few links from this forum on the gmt but can't seem to find any but yours. I know its been discussed several times. AU can you or others who own a gmt help him? Settings, like with anything, are very important based upon the ground you're detecting. GL!
"Months before the heated contention between the Bureau of Land Management and Nevada cattle rancher Cliven Bundy, purportedly over protecting an endangered species of desert tortoise, the BLM was euthanizing the tortoises in droves."