If you can dowse, then you need this book. It explains exactly whats going on and how to read your findings. Follow the instructions and you can judge the depth, flow rate and direction of flow of underground water sources, find static bodies of water, and even decide if its fit to drink or an old septic tank.
Several dowsing and divining techniques are described in detail including water divining, map dowsing, and divining by affinity.
Skeptics can pick up a pair of rods, follow the beginners instructions and see for themselves if they have the knack or not. You don't use loose metal sitting in a handle. Just use 2 bits of bent metal cut from wire coat hangers. The trick is to hold the sticks tightly and have your arms bent slightly and held under tension. If you can dowse then the bars will actually squirm in your hands. Its disconcerting the first time it happens.