Bathymetric data, which includes information about the depths and shapes of underwater terrain, has a range of uses, including:

Bathymetric surveys provide the data on which nautical charts are based.  These charts guide mariners much as road maps guide motorists, ensuring safe and efficient maritime transportation. Bathymetric maps are becoming increasingly important as scientists seek to learn more about the effects of climate change on the environment. Bathymetric surveys can alert scientists to ongoing and potential beach erosion, landslides, sea-level rise, and subsidence (land sinking). Scientists also need current/updated bathymetric survey data, which is critical to support the creation and development of hydrodynamic models. Bathymetry is also a key element of biological oceanography.  The depth and characteristics of the seabed define the habitat for benthic (bottom-dwelling) organisms, and are fundamental parameters of marine ecosystems.  Scientists increasingly rely on high-resolution bathymetry in their efforts to determine where fish and other sea life will feed, live, and breed. For more information:
Office of Coast Survey
Sea-floor Mapping, NOS Education

...