.... If you are in the middle of nowhere a pi machine is deepest. In nails like he said the Deus, e
3030 or a few others.
And humorously, there will be well-meaning newbies who will insist that they want "depth at all costs". And when you warn them that those "deepest seeking machines" will ring the bells of Notre Dame over every single nail, staple, BB, etc.... they will insist they're willing to "dig all" in order to "get the most depth".
But I have a sneaking suspicion that they will quickly go psycho, if they tried to do that.
For example: There is a certain park in San Francisco CA, where thousands of silver has come out of a certain field at this park, over the past 40-ish years. And it has always been perfectly stratified, where .... the 1940s silver was, for example, 6" deep. And the 1920s silver was 7 or 8" deep. And the 1900-ish losses (barbers) were 8 to 10" deep, etc... And we know for a fact that this field was heavily used in the 1870s to 1900.
Thus it stood-to-reason that seateds were "just out of reach". Eh ?
So one day, my buddy and I decided we'd take a Minelab GPX 5000 there, which can effortlessly get coins to 1.5 ft. deep ! Who could ask for anything more, eh ? Certainly seated coins will be "jumping out of the ground" , eh ? We were in for a big surprise, when we realized we could scarcely move the coil a few inches in any direction, without hearing a constant bombardment of pinheads, staples, nails, ttteeennnsssyyyy foil turds, etc.... We immediately went back to our "wimpy" standard coin machines that have disc. on them. Doh !