Has anyone any suggestions for tracking the path of plastic water main pipes buried underground? I want to extend the cottage a bit, and I know there are two pipes for neighbours' supplies in the ground (its a grassy area) but the overall plan which shows them in the deeds is at too low a scale to be accurate. I wanted to be sure where they were before I do anything. I've tried dowsing in the past and don't seem able to do it, so that's probably out. Any other ideas?