The dynamic equations of remotely operated vehicle (ROV) motions in deep water exhibit a highly nonlinear nature. Some of these nonlinearities are simplified for the ease of modelling and only motion in the horizontal plane is considered. A variable structure system (VSS)/sliding mode control (SMC) application is pursued as the control strategy. A variety of parametric selections are made to form this VSS/SMC strategy. An insight is provided into making these choices using a sliding stability argument. A set of digital simulation results are also presented to demonstrate the system behaviour in terms of the parameters of the SMC selected.