Abstract
We develop a new underwater robot for core sampling in this paper. Conventionally, penetration of a sampler into soil is done by gravity in many cases. The penetration force of the developed underwater robot is generated by the thrusters installed on the robot. Since the robot has naturalbuoyancy, it can be easily moved by the thruster force. The system hardware is explained and the basic performance of the developed robot is described. Moreover, the experimental result at Lake Biwa shows the usefulness of the robot for core sampling.