Abstract: A composite structure of lightweight is used as a tensioned tether element for mooring of offshore facilities. The composite structure comprises bonded inner and outer tubular members having an annular space therebetween. Aramid or other fibrous, high strength material is bonded to the inner surface of the outer tubular member to provide additional tensile strength thereto. The remainder of the annulus between the inner and outer tubing may be filled with a foam material such as polyurethane foam. The composite structure can be made so as to be of neutral, positive or negative buoyancy. The composite allows greater tensile loadings than steel materials by themselves at greatly reduced weight.