Georadiolocation is an effective tool to explore fresh water basins. When georadar is transported along the water surface by a small boat the bottom profile and the thickness of bottom sediments can be determined as well as sunk objects can be discovered. Investigation of a boundary between fresh and saline water in the estuaries of the rivers flown into the sea is a new field of georadars application. There is a possibility to determine damping factor, water electrical conductivity and, hence, water mineralization with the use of reflected signal amplitude.