Thank you for your response. About the Geonics EM61-MK2; let me do the next scenario; let say the area has a lot of nails and bottle caps, also a few cans; this equiment can ignore them or they would affect the performance of this equiment.I wouldn’t use hobbyist equipment for large area searches. Depending on the size of the area to search, I would use a Geonics EM61-MK2 or EM31 with a decent GPS receiver.