What technology do scientist use only to measure ocean depth?

Scientists primarily use sonar technology to measure ocean depth. Sonar, which stands for Sound Navigation and Ranging, emits sound waves from a ship or submarine that bounce off the ocean floor and return to the source. By calculating the time it takes for the sound waves to return, scientists can determine the depth of the water. Additionally, multibeam and sidescan sonar systems provide detailed bathymetric maps of the seafloor.