Fiber-optic-tethered unmanned submersible for searching submarine cables

A newly developed, fiber-optictethered, unmanned submersible called MARCAS (Marine Cable Search System) has been operating successfully. The mission of MARCAS is to inspect submarine communication cables and the seabed up to 200m in depth. MARCAS has dc and ac magnetometers (proton magnetometers and fluxgate magnetometers) and a metal detector in order to find and trace the cable even if buried under the seabed. A wavelength division multiplex optical fiber transmission system has been developed for the data transmission between the submersible and the mother vessel. MARCAS can be equipped optionally with soil property testing instruments. These characters will be discussed.