The autonomous underwater vehicle(AUV) Guanay II was designed to navigate on the surface of the sea, and to realize a vertical immersion in specific points. This vehicle has three thrusters located on stern, oriented to provide propulsion and yaw control on the horizontal plane. On the other hand, the immersion system used in the Guanay II is based in the change of the buoyancy of the vehicle, by using a piston system. Therefore, the vehicle does not have the ability to navigate in immersion, due to its design, which the inclination of the vehicle (pitch angle) cannot be controlled. In this work, we show the design a vector propulsion system for the vehicle Guanay II, which will allow to control the pitch of the AUV in immersion. For this purpose, we have provided to the two laterals thruster the possibility of varying their propulsion angle on the vertical plane, using two servomotors. Next, we will show the design and the results obtained.