Similar in operation to both Main Lift Cables and Tethers, these cable/umbilical types provide electrical power, electrical and/or optical signal and occasionally hydraulic or pneumatic services between land or an off-shore vessel and a sea-bed crawling vehicle (e.g. trenching, sampling or surveying).

Often armoured for both mechanical protection and tensile strength, cables of this type may have to withstand gruelling dynamic use and damaging external effects from the seabed conditions. Where weight is a consideration however, synthetic fibre reinforcements may also be considered.