" it's a good bet that the answer will lie in geophysics rather than the paranormal."

Heavens! I had to sit down for this. I am forced to agree with Shaw. I will be in shock for the rest of the day!

I can only comment on water divining although I have been on locations where witch doctors have been brought on site to sacrifice a veritable zoo in order to bring "luck"

Before you can have a tool for testing you need to determine what you are testing for. Therein lies the problem. Is it an electrical or magnetic anomaly being sought, or something else entirely? The only tool I have used for flowing water is a spinner survey and that needs to be immersed. What is required is a tool that will remote sense. It is generally cheaper to drill a well than throw fancy geophysics at the perceived problem. Once a well is drilled it is easier and more accurate to perform pumping tests to determine deliverability than put tools downhole to measure porosity and permeability. (on the basis one swallow does not a summer make)

The practise seems to extend way back in prehistory and still exists today. To my way of thinking it has more going for it than a belief in faeries or religion.