The problem of optimal trajectory planning of the unmanned underwater vehicle (UUV) is
considered and analytically solved. The task is to minimize the risk of detection of the moving object
by a static sonar while moving between two given points on a plane. The detection is based on the
primary acoustic field radiated by the object with a non-uniform radiation pattern. In the first part of
the article, the probability of non-detection is derived. Further, it is used as an optimization criterion.
The non-uniform radiation pattern of the object differentiates this work from previous research in the
area. The optimal trajectory and velocity law of the moving object are found, as well as the criterion
value on it.