Folk Dowsing

You can find what you're looking for using a dowsing rod or pendulum. If you Search while wielding a dowsing rod or pendulum, in addition to the normal checks for Searching, the GM rolls a secret Survival check for you to detect the largest source of water, oil, or another natural non-bodily fluid in the area. Even if the liquid is Concealed from you—for example, if it stems from an underground spring or is piped through a wall—this technique points you in the right direction. The GM determines the DC, which is usually the trained simple DC with a hard or very hard adjustment if the source of water is small.

If you're an expert in Survival, the GM also makes a Survival check for you to detect sizable deposits of metal, minerals, and nearby graves. The DC is usually the expert simple DC, with DC adjustments for smaller deposits.