"Bathymetrical" is a word used to describe the study of underwater topography, or the measurement of depths in oceans, lakes, and other bodies of water. There are several synonyms for this word that can be used interchangeably such as oceanographic, hydrographic, and underwater topographical. Other synonyms include nautical, marine, aquatic, subaquatic, and subaqueous. Each of these words carries a similar meaning and provides a different way to describe the depths of bodies of water. Whether describing the depths of the ocean or a small pond, these synonyms for bathymetrical can provide a more varied and interesting way to discuss underwater topography.