This paper introduces the underwater robot HAL-urabo. HAL-urabo is a hovering type autonomous underwater vehicle (AUV) designed to take part in student competitions, and to develop a functional lowcost AUV kit, with fully documented physical and electrical design and an open source code. The vehicle has an overall length of 0.83m and weighs 11kg, with a maximum depth rating of 10m. The basic concept behind the development of the vehicle is that a person without expert knowledge of ocean engineering could purchase the necessary components, and build an AUV for a budget of around 300,000yen, or US$3,000.