Editing Geographical exploration (section)

==Underwater exploration==
{{main|Underwater exploration}}

===Objectives===
The scope of underwater exploration includes the distribution and variety of marine and aquatic life, measurement of the geographical distribution of the chemical and physical properties, including movement of the water, and the geophysical, geological and topographical features of the Earth's crust where it is covered by water.<ref name="Britannica" />

Systematic, targeted exploration is the most effective method to increase understanding of the ocean and other underwater regions, so they can be effectively managed, conserved, regulated, and their resources discovered, accessed, and used. The ocean covers approximately 70% of Earth’s surface and has a critical role in supporting life on the planet but knowledge and understanding of the ocean remains limited due to difficulty and cost of access.<ref name="NOAA" />

The distinction between exploration, survey, and other research is somewhat blurred, and one way of looking at it is to consider the baseline surveys and research as exploration, as previously unknown information is gathered. Updating and refining the data is less exploratory in nature, but may still be exploration for the people involved, in the sense that the experience is new to them.

===Status===
According to NOAA, as of January 2023: "More than eighty percent of our ocean is unmapped, unobserved, and unexplored."  Less than 10% of the ocean, including about 35% of the ocean and coastal waters of the United States, have been mapped in any detail using sonar technology.<ref name="NOAA/NOS" /> According to GEBCO 2019 data, less than 18% of the deep ocean bed has been mapped using direct measurement and about 50% of coastal waters were not yet surveyed.<ref name="IHO DCDB" />

Most of the data used to create global seabed maps are approximate depths derived from satellite gravity measurements and sea surface heights which are affected by the shape and mass distribution of the seabed. This method of approximation only provides low resolution information on large topographical features, and can miss significant features.<ref name="NCEI" />