By boarding on a manned deep sea submersible, it is possible for researchers to go down to the deep sea floor and perform minute observations while confirming the situation of the sea bottom by themselves. It is, however, very dangerous for the manned submersible to approach narrow spots like fissures at the sea bottom or to access near cliffs. Considering these matters, the deep sea TV observation ROV has been developed. This ROV is one of the observation tools which is installed in deep sea submersibles and it can be used for investigation of constricted sites where the submersible cannot approach. This TV observation ROV is a launcher-type ROV. The entire system of this ROV is constructed, supposing that the launcher would be fixed on the "Sinkai6500" , which is one