Shows a local history of weather patterns. It would seem beneficial if the cellars could be located on their own map or by a series of markers pointing a direction from where to leave the coastline to reachinland by river. Westminster, VT at 1000 ft altitude. This device came about from aircraft usage. At 100 feet depth it did locate a human skeleton - conditions were ideal.
Ideal conditions are where the soil is homogenous.
But, At depths of 6 the readings would have some reliability. For example, along a portage path one might expect to pick up metal shapes such as copper, silver, and tin as well as pottery or shards. So long as the search objects had a different dielectric than the soil, a reading would occur. Knowing a pathway location through a swamp would be an ideal method of search. Compacted soil would also show up.