Abstract <p>The problem of the plane-parallel motion of a trimaran robot is considered. The robot is a symmetric structure consisting of a streamlined platform (body) and three identical floats rigidly connected to the body: one front and two rear. Motion in a fluid is provided by controlling the rotational speed of the flywheel that is installed inside the body. The control task is to ensure that the body advances in the set direction. It is assumed that the robot is initially at rest. An analytical method is proposed for finding the values of the geometric parameters and control parameters that raise the acceleration efficiency of the system.</p>