The task of survey vessels is to map the bottom, and measure the characteristics of the
benthic zone, full water column, and surface for the purpose of: •
hydrography, the measurement and description of the physical features of oceans and other natural bodies of water, and the prediction of their change over time, for the primary purpose of safety of navigation and in support of other activities associated with those bodies of water, • general
oceanography, the scientific study of the oceans, • mapping of
marine habitats as part of the process of assessing the state of the ecology, • measurement of
environmental impact of natural and anthropogenic changes, • planning of
marine salvage, the process of recovering a ship and its cargo after a shipwreck or other maritime casualty, •
dredging, the excavation of material from underwater, to recover materials or to alter the bottom profile, usually for navigational of construction purposes, •
underwater construction, which is industrial construction in an underwater environment, •
coastal engineering, the branch of civil engineering concerned with construction at or near the coast, and the development of the coast itself, •
maritime archaeology, the study of human interaction with the sea, lakes and rivers through the study of associated physical remains, •
underwater mining and
extraction of petroleum. ==Survey equipment==