Water Divining
My late father was a water diviner. He didn't use the skill as a party trick, it had a very practical purpose. We needed a bore hole dug on our property and he was able to pinpoint the exact spot where the most water could be found. When I was a kid water diviners were called in when a source of water was needed to be traced in my island home.
My father was also a geographical dowser too, which was useful if you needed to find a person or object. When the Stone of Scone went missing from under the Coronation chair got out his divining rod and led the police to the barn where it was housed on its onward journey to Scotland. We have photos of him with the Scotland Yard detectives.
I don't know how divining/dowsing works but I am of the opinion it is natural 'gift' and nothing supernatural is involved. Unfortunately neither my sisters of myself have the ability. One day it might be interesting to see if the grandchildren have it.