OKM GeoSeeker Mini - Underground Water and Cavities LocatorOKM GeoSeeker Mini Water and Cavity Detector Depth: 100 meter (328 ft) Water detector and cavity detector down to 100 meters (328 ft) depth Like the water detector OKM GeoSeeker, the GeoSeeker Mini utilizes a geoelectrical measurement procedure based on Schlumberger. The water detector that can also be used to detect underground cavities determines the soil resistivity. Based on that apparent resistivity of the ground the detector is able to detect