Underwater vehicles have developed greatly to the point that allowed their use in a variety of applications. However, using this kind of vehicles for in-service oil tank inspection is not yet advanced enough. As part of an effort to design a new class of underwater vehicles suitable for inspection, the present work ascertained requirements devoted to each component of those vehicles. A detailed design process was introduced and the main parts of the vehicle are described with emphasis on its related constraints. Finally, a control navigation strategy is proposed so that the vehicle will incorporate six degrees of freedom.