Which position fixing method is commonly used in hydrographic surveying to determine underwater locations?

The selection of surface positioning as the commonly used method in hydrographic surveying to determine underwater locations can be attributed to its effectiveness in mapping undersea features and ensuring accurate positions. Surface positioning involves the use of established reference points or surface vessels equipped with navigational aids to calculate the location of underwater targets.

Typically, the surface positioning method utilizes various technologies such as GPS and traditional triangulation techniques, providing high accuracy relative to the water's surface and enabling surveyors to correlate those readings with underwater data collected. This technique allows for real-time navigation and position fixing, essential for effective planning and execution of hydrographic surveys.

This method contrasts with other techniques such as satellite positioning, which can provide geographic coordinates but may not account for local variations influenced by water currents or tides during the survey. Radar positioning is primarily used for applications involving air or surface vessels rather than underwater mapping. Land-based surveying is generally unsuitable for hydrographic work due to the inherent differences in measuring underwater topography and features.

Thus, surface positioning effectively satisfies the need for precise positioning in hydrographic surveying, playing a vital role in accurately capturing the underwater landscape.