Ground Penetrating Radar (GPR) can be used in fresh water lakes and river. It cannot be used in salt water or brackish water due to the increased conductivity values of such waters. GPR is typically used in freshwater environments to determine bathymetry and sub-bottom stratigraphic sediment profiling. This method is used to identify natural features such as sediment stratigraphy and interfaces, as well as natural and man-made objects including cables, pipes, boats, outboards, logs and other artifacts buried deep in sediments. It can also be used in frozen environments to measure thickness and determine the structural aspects of ice and snow.