What frequency range is commonly used in SBES?

In Single Beam Echo Sounding (SBES), the frequency range commonly used typically falls within the range of 10-30 kHz. This frequency range is optimal for achieving a balance between the penetration of sound waves into the water and the resolution of the data collected. Frequencies higher than 20 kHz can provide more detailed measurements and finer resolution, which is particularly useful in shallow waters where precision is essential for mapping the seabed and detecting features such as rocks, wrecks, or other underwater structures.

Utilizing higher frequencies also allows for better detection of smaller objects and improved clarity in the returned echo signals, which significantly enhances the quality of the hydrographic survey data. Therefore, the correct answer aligns with the commonly adopted practices in hydrographic surveying, where frequencies above 20 kHz are preferred for many applications.