The Civil Engineering Laboratory (CEL) has recognized the need for reliable simulation methods for predicting the motions of underwater cable structures, and is engaged in a major effort to develop the capability for analyzing such structures during deployment, operations, and recovery. To accomplish this goal, work is currently underway on a wide range of studies, ranging from prediction of barge motions to development of new drag measurement techniques. This report is the first in a series that will deal with evaluations of computer models used by CEL for the analysis of underwater cable structures. In this report results from a finite-element program, SEADYN, and a lumped-mass program, SNARLG, are compared to experimental data from a series of tests conducted with 6-ft long cables. A total of 17 comparisons were made, including: single point mooring relaxations, simulated anchor-last deployments, bi-mooring relaxations, and single and dual cable suspended loads with forced oscillations of the cable. Graphical comparisons are included showing: nodal positions of the cable, velocity of the anchor/buoy, and tensions at the fixed end of the cable. These comparisons have shown that both SEADYN and SNAPLG are useful tools for simulating the dynamic behavior of ocean cable structures. Both models, however, had difficulty simulating a stiff cable and slack conditions.