Abstract
Deepest Remotely Operated Vehicle ”Kaiko”, owned by Japan Marine Science and Technology
Center (hereafter； JAMSTEC), had lost own vehicle during the research operation by the acci
dent of snapping the secondary. JAMSTEC and other Japanese governmental organizations
searched the missed vehicle as well as we could. However, it has been missing ever since. The
search activities, which many Japanese organizations cooperated and carried out, arc summarized
in this subject.
