Underground Water Detectors locate subsurface water by reading natural electric field signals through ground electrodes and flagging abnormal zones where aquifers are likely. Survey depths run from 100 to 500 m, with optional ranges of 500 to 1000 m for deep borewell planning. Up to 18 channels and 22 electrodes collect data simultaneously at 0.001 mV resolution, with a measuring cycle of 2 to 15 minutes. Automatic analysis draws curve maps, profile maps and 3D renderings and marks the recommended drilling point. A 2 kg host with built-in power cells runs 8 hours in the field. Typical uses include farm and residential water supply, drought relief, mining and environmental restoration.