This paper presents novel design of underwater robot for exploring abandoned mines. The hazardous environment of such mines due to unknown hydrodynamic forces and faulty navigations, brings the need of developing a reliable system able to be controlled autonomously. This capability highly rely on the basis of low level control and mechatronic architecture of the robot which demonstrate robot potential for performing real-time operations. Following, describes rapid prototyping during development phase of the robot. Further, it investigates on mechatronic development of main controller unit, propulsion system and ballast.