The purpose of the paper is to analyze the peculiarities of the partially cavitating vehicle dynamics. The research method is a computer simulation using the approximation model of the unsteady supercavity basing on G. V. Logvinovich's principle of independence of supercavity's sections expansion. A method of determination of the balanced motion parameters for the partially cavitating vehicle is elaborated. The examples of computer simulation of the partially cavitating vehicle motion are given, incluing the vehicle speeding-up and deceleration. The longitudinal motion of the balanced partially cavitating vehicle is is shown to be statically unstable on depth. In this case, the motion stability loss occurs in "hard" non-oscillatory manner, unlike the supercavitation case. The methods of stabilizing the partially cavitating vehicle motion are proposed. The effect of cavity ventilation on the dynamics of the cavitating vehicle is studied.