The underwater robot buries cables, repeaters and cable joint boxes in order to protect submarine cable systems from fishing activities or anchors of large vessels, and also carries out localization of a failure point of buried cables, or on the status of the failure point.
Also, it removes obstacles on cable routes, or supports an operation to recover cables onto the ship for the cable movement or repairs.

The underwater robot is supplied electric power from the mother vessel via an umbilical cable, and is remotely operated from the vessel, using data from the still camera and sonar on it.

The remotely operated underwater robot is called "ROV" which is an acronym for Remotely Operated Vehicle, and the KCS's ROV is called MARCAS(Marine Robot for Cable work Assistance and Surveillance).

ROV MARCAS-IV on
the KDDI OCEAN LINK

ROV MARCAS-V on
the KDDI CABLE INFINITY