American Horse
AKA "Mustang"
I saw it work very reliably by employees of our village water corporation. They had several trained dowsers, and they produced reliable results. That was before electronic methods (Holey Moley) came into subscribed useage. I was a builder from 1968 to 2006, and most of my houses were customers to be connected to that particular water company's lines. Lots of water lines/mains were buried without a detection wire, so they had to use the dowsing method to locate.