Abstract: The aim of the paper is checking possibility of building active stationary sonar designed for work in very shallow water, depth 8 - 10 m. Sonar is designed for monitoring very weak and moving targets by TS about -20 dB at the range up to few hundred metres. This paper presents construction of wide-sector sonar consists of two linear transducers. Beampatterns of the transducers are adjusted to conditions existing in very shallow water, particularly to minimize bottom and surface reverberation and effect of multipath propagation. Below are presented results of tests and measurements made for different types of targets and different environmental conditions - including: state of the sea, strong aeration of the near surface water, and influence of different sound propagation conditions for detection of the targets. The paper contains results of influence few types of signal processing for improvement SNR, thus increasing probability of the targets detection.