What is bathymetry all about?
Yet another view of a watershed is to look beneath the surface of a lake on a hydrographic (bathymetric) map that shows contour lines of the water at different depths. The closer the contour lines for different water depths are together, the steeper the drop-off into deeper water. There is a long deep trench through the center of Crystal Lake where water depths exceed 150 feet (~ 50 meters).
