Autonomous underwater vehicle

An autonomous underwater vehicle comprising:

• a position detector that detects a position of the position detector relative to an underwater structure;
• a propulsor;
• control circuitry configured to
• control the propulsor based on a detection result of the position detector such that the autonomous underwater vehicle moves along the underwater structure and
• grasp a position of the autonomous underwater vehicle;
• an underwater potential sensor that three-dimensionally measures a potential gradient in water;
• and
• a metal potential sensor that inspects an electric field producing body that is a part of the underwater structure or a sacrificial anode, wherein:
• the control circuitry specifies a position of the electric field producing body by mapping an underwater electric field from the potential gradient measured by the underwater potential sensor in accordance with movement of the autonomous underwater vehicle;
• the control circuitry controls the propulsor such that the autonomous underwater vehicle moves to and stops at an inspection position that is a position at which the metal potential sensor is opposed to the electric field producing body;
• and
• in this state, the control circuitry makes the metal potential sensor inspect the electric field producing body.