Sounding, in the context of hydrography, refers to the process of measuring the depth of a body of water using various methods and techniques. This could include oceans, seas, rivers or other major water bodies. Soundings are typically taken by survey ships or aircraft using acoustic technology, such as sonar systems, to send sound waves down into the water. The time it takes for the sound waves to bounce off the seafloor and return provides data on water depth. This process is critical in map-making, navigation, and in supporting various scientific and environmental research studies. The term 'sounding' originates from the Old English 'sund', meaning swimming, water or sea. The information gathered from these soundings is used to create nautical charts which help in safe navigation, planning marine routes, and developing strategies for resource exploration.

1. The ship's captain ordered a sounding to make sure they weren't in dangerously shallow waters. 2. The team of marine biologists performed a sounding to determine the depth of the area they were studying for their research on deep-sea organisms. 3. The divers took a sounding of the lake before they begins their search for the sunken artifact. 4. Before constructing the bridge over the river, engineers did a sounding to understand how deep the foundations needed to be. 5. The submarine utilized sophisticated sonar technology for sounding, determining they were in a trench approximately 3000 meters deep.

Sounding, in the context of measuring the depth of water, is an intriguing and ancient method used by sailors and explorers. This method was historically performed using a lead line: a rope with a lead weight at one end that was thrown overboard. The rope was marked with fathoms (a unit of length equal to six feet), and when the weight hit the seabed, the depth was read off the line. Today, the technology has advanced to use sonar echolocation, where a pulse of sound is sent into the water and the time it takes for the sound to bounce back is measured to determine the water's depth. Despite the technological advancement, the process is still referred to as sounding, preserving its rich maritime and exploration history.