Underwater apparatus

An underwater apparatus comprising:

• a housing configured to accommodate a certain device;
• a pair of cable couplings configured to include gimbals through which tail cables extending from the device to the outside of the housing pass, and the pair of cable couplings that connect the tail cables passing through the gimbals to a submarine cable;
• and
• a connecting holder configured to include gimbal rings fitted to the gimbals and to connect the pair of cable couplings to the housing via the gimbal rings so that the pair of cable coupling is rotatable relative to the housing, the connecting holder including an opening from which the gimbals are introduced toward the gimbal rings, wherein the connecting holder includes notches provided in an edge of the opening and the notches are formed by retreating the edge of the opening in directions away from the gimbals so that the pair of cable coupling is rotatable relative to the housing.