In this paper a mathematical model for the steering control system of submersible vehicle is presented. System has been analysed with numerical and graph-analytical methods. Different types of controllers: P, PI, PD and PID are investigated. Ultimate sensitivity tuning method (Ziegler-Nichols Second method) is used to establish initial controller parameters. Optimal controller parameters have been determined using a Fine tuning method. PD controller has chosen as the best option for the system. Two different criteria are selected to find controller’s optimal parameters: Integral Squared Error and Integral Absolute Error. Dynamical behaviour of the system has been simulated by Simulink and Matlab. Non-linear elements are added to protect a rudder/steering gear. A sea current as the dominant disturbance has been implemented in the system and its influence on the system has been investigated.