The objective of this book is to present the main theoretical approaches and models in shallow water acoustics as well as different experimental results. The focus is primarily concentrated on physical results describing the sound field in wave length. The authors show dynamic phenomena (tides, internal waves) from the perspective of acoustic influence as well as the scattering of sound over the macroscopic body in shallow water waveguide. The method of acoustic probing can be used by physicists, geophysicists, geologists and oceanographers.