A finite element geometric nonlinear analysis program has been developed for the analysis of single point sub-surface deep sea moorings. The effect of diameter of the cable (D), drag coefficient (Cd), rope length (L), current velocity (V), current profile and buoyancy (T) on the mooring configuration have been studied. A design chart has been prepared based on the results of the parametric study on 12 sizes of commercially available torque-balanced jacketed wire ropes. The design of buoy system using the developed design chart is illustrated. © 1991.