A numerical solution is presented for the three-dimensional transient motion of a marine cable towed by a vessel that can arbitrarily change speed and direction on the horizontal plane of the water surface. The solution is obtained by dividing the towed cable into η straight rigid elements. The translational and rotational motion of each element is described by its elevation and azimuth angles. The equations of force and moment equilibrium and the geometric compatibility relationships for each element are used to form a system of 2n ordinary differential equations which are solved numerically using the Runge-Kutta method. In order to illustrate the solution, a range of results are presented for cable tension and towed cable motions as the towing vessel carries out turning maneuvers.