my grandfather was a dowser. for some reason when they built their retirement home, they relied upon ‘experts’ to locate the water supply. the process took two years, and included spectacular blasting, etc.. finally grandpa got frustrated and took out his divining rod. he told the experts where to dig. the scoffed and he insisted. they’re still getting water from that spot, and the three failed holes were filled up.
when we drilled for my well in Maine, i had it dowsed. they hit it the first time.
That’s how it was done in Connecticut when I lived there many moons ago.
I met a dowser once, he used copper rods. He asked me if I wanted to try it. I said sure, but it’s all BS. He pointed to where a water line was and told me to walk over it. The damned things crossed one another. Freaked me out because I was making damned sure my fingers were still so not to impart any motion into the rods. Weird feeling to see them move on their own with no assistance from me.
Not sure if it’s all BS after that happened.