The underwater robot competition in international conference Techno-Ocean 2021 was held to advance underwater technology, in Dec. 2021. The competition consists of five leagues including AUV (Autonomous Underwater Vehicle) league, and Kyushu underwater robotics which is the Underwater Student Project team at our university that joint the AUV league using developed AUV. The wet test of the AUV league includes a Gate Pass mission which requires passing through an underwater green gate, Buoy Touch mission requiring contact with the yellow and red buoys, and Special mission requiring contact with the Pinger which has an unknown location. Our AUV navigates by image processing using underwater camera to achieve the mission. This paper explains the AUV system, the mission strategy and detail of image processing.The 2022 International Conference on Artificial Life and Robotics (ICAROB 2022), January 20-23, 2022, on line, Oita, Japa