Bathymetry
Meaning
Measurement of seafloor depth, allowing submarine relief to be represented with the same precision as a land topographic map.
Reference source
The Canary Islands topobathymetric relief map — Aspect of the sea bed and geology
https://www.ieo.es/documents/10640/35483/mapastopo-FOLLETO_CANARIAS.pdf/339933b3-53d9-468a-bfd7-e0489664855b