A large capacity, cable turntable assembly is provided for use in connection with laying along lengths of underwater cable. A turntable is provided which has a planar, toroidal floor bounded by an upright, interior wall surrounding the axis of rotation and an upright, exterior wall spaced apart from the interior wall. The walls and floor define an open-top chamber for receiving a long, coiled length of cable. A multiplicity of fluid-cushion bearings are secured to the turntable below the floor and permit rotation of the turntable on a supporting surface when the turntable is loaded with cable and when the cable is removed. The fluid-cushion bearings also permit lateral movement of the turntable over distances. Water is supplied under pressure to the bearings to facilitate movement of the turntable. The turntable may be positioned on a shoreside-support, permitting rotation of the turntable in order to load cable onto the turntable. The turntable may then be moved laterally onto a support surface on a floating platform, such as a barge. During the loading process, the barge is ballasted to maintain a level attitude. When the turntable is on the barge, the central core, which forms a lateral bearing surface, is positioned in the center of the turntable. In order to permit the lateral movement of the turntable, the central core may be either recessed into the deck or made removable. The turntable is driven by peripheral drive wheels.