JAMSTEC has proposed an operation of multiple AUVs using an ASV (Autonomous Surface Vehicle) to improve survey efficiency. For this purpose, an ASV “MAINAMI” with a length of 6 meters has been developed since 2013. The vehicle is equipped with an acoustic communication device and a satellite one, in order to relay information between an AUV and operators on a ship or on land. In February 2016, its sea trials were carried out at Suruga-Bay. The performance of its solo navigation was verified through the sea trial. And, the ASV succeeded in tracking of a deep-tow as a simulated curing-type AUV.