We use it for cemetery reconstruction and have been very successful in finding blocks of graves.
This past year, we used Ground penetrating radar on one pioneer burial yard and checked it by witching.
I was very skeptical and similarly thought you'd get water nearly anywhere you drill. At one job, my uncle told them where to to drill, they'd get water at 18-20' but not much and at 50' there would be good water. Exactly 20' there was a poor vein and (he missed it) at 55' there was a perfect supply.
I'm a believer.