An observation of sea floor by a hovering type AUV HOBALIN with offshore multi-purpose work vessel Kaiyu at Middle Okinawa Trough

A real sea survey result of sea floor at Middle Okinawa Trough by a hovering type AUV (Autonomous Underwater Vehicle) HOBALIN is reported. The depth of the survey target area is almost the intended limit of the AUV and it was the first time for the AUV to dive down to that depth since the AUV dived first time into the real sea almost one year ago. The operation of the survey with the AUV was done with a nongovernmental and non-academic commercial offshore multipurpose work vessel also as the first time. During the survey dive, the AUV succeeded to avoid chimneys with more than 10m height, which was done by the obstacle avoidance mechanism based on a line laser and USB camera with newly developed algorithm, and also succeeded many high-resolution photographs. By this survey cruise, we can conclude that the AUV is almost ready to be used heavily and effectively by general users.