Intervention in deep and ultra deep water requires increasing amounts of power on the seabed, not just to meet current needs, but to supply the greater demands of subsea processing. If cable sizes are to be kept manageable, efficiency will have to be improved. This can be achieved by using higher voltages. Electrical cables that are deployed from the surface are described as 'dynamic' and have to be capable of withstanding fatigue. Two elements are critical to their integrity; the first is their strength member; and the second is their insulation. Deep Tek Ltd. has taken an inventive approach to providing power in deep water, through the development of its patented Winder. This simple piece of technology wraps conductors and optics around a fibre rope, to form a de facto hoist umbilical as underwater equipment is deployed, and unwraps them as it is recovered. In this way the properties of man-made fibre rope can be harnessed and combined with power and signals, to create industrial capability in the form of a 'load-bearing' ROV.