Me too, done it myself.
Years ago I watched a programme on TV called Donovan the Diviner and it followed the work of Donovan who worked in the West Country. He went onto the Isles of Scilly (I think). He was only paid on results so he had to find what was needed, his wife also worked with him and she was more sensitive to certain aspects, so he divined a field and found a suitable spot, there were of course many, but he picked one in particular, his wife then followed with a multi coloured disc and whatever colour she was holding denoted different things, they wanted a certain flow and a continuous one. Water can flow and then stop, it can be brackish or it might hardly flow at all. Wifey confirmed the depth and flow and they bored a hole, they passed water they didn't want and got to the depth prescribed. A year later the bore was still flowing at the rate they had said.
Frisbee