Abstract
The Japan Agency for Marine-Earth Science and Technology acquired an autonomous underwater vehicle, the URASHIMA, in 2000. It has capacity to cruise for 300 km, and to dive up to 3,500 m depth, and it can approach waypoints correctly using inertial or acoustic navigation during autonomous cruising. Autonomous underwater vehicles are expected to explore environmental problems by measuring various oceanic data. Through sea trials, we have been developing key technologies for the vehicle, such as navigation and power sources. This paper describes the vehicle system and sea trial results.