For the purpose of observing leaks of CO_2 in CO_2 ocean sequestration, submarine robots that can make observations independently and stay over the seabed against the current for long periods of time are needed. In order to achieve this objective, a novel submarine robot was proposed. The robot is moored, its position is controlled by tether, and it generates electricity with sea current power generation system. After that, the prototype submarine robot "Anchor Diver" was developed. Anchor Diver is moored by one tether, moves with horizontal and vertical rudder and goes upstream with reel mechanism. In addition, the use of a movable anchor and generator as a propeller enables Anchor Diver to enlarge its range of activity. This paper describes the detailed development of Anchor Diver and experiments in the water.