Many ROV systems are launched & recovered by a tether management system (TMS) Sometimes referred to as a “cage” or garage. The TMS offers a stable platform for the ROV to operate from, therefore the main lift cable supports the weight of the cage, the ROV, & ancillary equipment. 
The main lift cable will provide the total services of the vehicle for power, high voltage, CCTV, signal, & communication via optical, coaxial or twisted & balanced pair conductors.
The strength / mechanical support can be provided by contra helical armour, or multilayer aramid braids. Weight, ruggedness, and physical protection are important considerations in the design & construction of these cables.