<p>Developing marine resources has emerged as a pivotal strategy for future marine energy development, with remotely operated vehicles (ROVs) boasting exceptional performance playing a crucial role in this endeavor. This paper presents a high-precision sliding mode tracking control strategy with user-definable convergence time for ROV motion systems facing external disturbances, aiming to ensure the ROV system’s stability, accuracy, and rapidity. Firstly, a novel predefined time convergence (PTC) stability criterion is devised to design ROV controllers. Compared to existing predefined time convergence stability criteria, the predefined time convergence controller designed based on this new criterion has advantages such as fewer control parameters and simple structure. Subsequently, leveraging an improved nonsingular predefined time convergence sliding mode (SM) surface and the novel predefined time convergence stability criterion, a rapid convergence sliding mode controller (SMC) is formulated for the ROV system, ensuring that the trajectory tracking error (TTE) converges to the equilibrium point within a preset timeframe. Numerical simulation results indicate that utilizing the PTC sliding mode controller devised in this study, the TTE of the ROV converges to zero within a user-specified timeframe. The speed function effectively accelerates the convergence rate of the trajectory tracking error, achieving a precision of 0.00005, thereby validating the effectiveness and high tracking accuracy of the algorithm proposed in this paper.</p>