The Infante AUV has been designed as an environment survey tool for coastal waters. The vehicle is a major re-design of the MARIUS AUV that was developed in the scope of the MAST-II SOUV EU Project coordinated by the IST/ISR. The Infante AUV is 4.5 meter long and 1.9 meter wide (including control surfaces) and is propelled by two electric thrusters. It is also equipped with horizontal and vertical maneuvering tunnel thrusters. Precise vehicle steering is achieved with four control surfaces in the vertical plane and two rudders in the horizontal plane. Energy is stored in two banks of lead acid batteries for propulsion and two separate banks for computers, sensors, and surface actuators.