This paper focuses on the thruster dynamics of a hybrid unmanned underwater vehicle (UUV) with the help of a system identification method. This system identification method allows the building of a transfer function model or a state space model, which can be used as an SISO (Single–Input–Single–Output) system or a MIMO (Multiple–Input–Multiple–Output) system. These UUVs are very helpful when it comes to underwater operations such as pipeline inspections, underwater pick-and-place operations, rope-cutting or any military purposes. To conduct a smooth operation of these vehicles precise motion or path planning is needed, which can be achieved by actuators (like thrusters or propellers) attached to these vehicles. So, an underactuated system has been developed with five thrusters and an open-loop simulation has been carried away with MATLAB software to see the behavior of the thrusters at a certain input voltage level.